Military chemistry workbook for junior officers

CHEMISTRY IN SUPPORT OF MULTI-DOMAIN, 

TACTICAL LEVEL ENGAGEMENT

The intent of the workbook

The workbook of military chemistry for tactical level provides junior officers with a foundational understanding of the chemical reactions behind the most common phenomena in the battlefield. The fundamental understanding of chemical reactions helps officers to recognise dangerous incidents on the battlefield and supports their action for mitigation of the caused problems.

Both theoretical exercises and field demonstrations help officers to apply the foundational knowledge in practice. An officer should lead his/her troops to success in tactical missions while utilising the benefits or preventing the endangering incidents based on chemical reactions.

The workbook is divided into four sections, each focusing on essential competencies required in the battlefield: 1. Sustain, 2. Survive, 3. Manoeuvre, and 4. Fires. Each section uses the chemistry to understand better the fundamentals of the battlefield and therefore build insight into the behaviour of the socio-technical system (fighting unit) in the military environment under the enemy effect. 

Each section first gives an orientation to application or incident caused by chemical reaction, then provides a short introduction to the theory, third provides examples of the chemical reaction in the field, and finally, offers challenges or exercises to be solved as homework or during the fieldwork. 

Sample history of chemical weapons development and use

Cacodyl is highly toxic and spontaneously flammable in dry air. Its fumes have an obnoxious smell and are highly irritant to the eyes, skin, and nasal passage. Other cacodyl compounds, such as cacodylic acid and cacodyl cyanide are similarly unpleasant.

The U.S. Armed Forces were using Agent Blue, one of the so-called 'rainbow herbicides,' consisted of a mixture of cacodylic acid and sodium cacodylate. It was used in powder form from 1962 to 1964 and then in the aqueous solution until 1971. The herbicides were deployed as part of the United States' resource denial' programme to deprive the Vietcong of food by defoliating forests and cultivated lands. Subsequent studies revealed that the program had little impact on the enemy soldiers. Vietnamese civilians, on the other hand, suffered immensely.

• U.S. employed mixtures of cacodyl and diphenylcyanarsine in naval munitions before II WW
• 1916 – 1918 in WWI, there were close to 92,000 deaths and more than 1.3 million casualties on all sides due to gas attacks. 
• 1860 a captain proposed the use of cacodyl as a chemical weapon
• 1857 Russians tested cacodyl filled artillery shells. The cats they used in tests survived but with torn eyes. Russians cancelled the project.
• 1855 a U.K. chemistry proposed to use cacodyl acid as chemical warfare against Russians in the Crimean War. Michael Faraday thought the idea barbaric, and MoD rejected the proposal.
• 1847 scientists experimented with cacodyl and organoarsenic chemistry and pioneered in synthesising organometallic compounds.
• 1757 cacodyl was first synthesised by Louis Cadet. He heated potassium acetate and arsenic trioxide in a furnace and distilled the product into a receiver.

1. Sustain

A mechanised platoon is deployed for defence. All four BMP-3 vehicles are positioned to optimise cross-fire to kill-zones. The enemy has reportedly been using drones to scout ahead of their attack colons and using visual and thermal imagining to detect military positions. The platoon commander orders the BMP-3 crews to shut the engines to minimise the heat radiation from the positions. After waiting for 6 hrs, the enemy drones are detected flying over the positions, and soon after that, the enemy formation is sighted at 2 km distance. The platoon commander commands the engines started and enemy engaged—only two of the four BMP-3 starts. The remaining two were not able to start their engines. Why did this happen?

1.1 Energy and Electrochemistry

Aim: Officers shall understand the chemical reactions behind storing and releasing energy for electrics. They can estimate the durability of each source of energy in a particular environment.

Orientation

Batteries are used to provide back-up electricity in various military vehicles and platforms. The electricity runs sensor and weapon systems, comms and battle management systems, and protection systems. Energy is stored into batteries based on a chemical reaction. An officer shall be able to estimate the duration of energy stored in batteries if engine and generator are not used

Theory

Voltaic (galvanic) cells are electrochemical cells that contain a spontaneous reaction, and always have a positive voltage. The electrical energy released during the reaction can be used to do work. A voltaic cell consists of two compartments called half-cells. The half-cell where oxidation occurs is called the anode. The other half-cell, where reduction occurs, is called the cathode. The electrons in voltaic cells flow from the negative electrode to the positive electrode—from anode to cathode (see Figure below). (Note: the electrodes are the sites of the oxidation and reduction reactions). 

For an oxidation-reduction reaction to occur, the two substances in each respective half-cell are connected by a closed circuit such that electrons can flow from the reducing agent to the oxidising agent. A salt bridge is also required to maintain electrical neutrality and allow the reaction to continue.

 

The Figure above shows that Zn(s)Zn(s) is continuously oxidised, producing aqueous Zn2+Zn2+:

Zn(s)→Zn2+(aq)+2e−(1)(1)Zn(s)→Zn2+(aq)+2e−

Conversely, in the cathode, Cu2+Cu2+ is reduced and continuously deposits onto the copper bar:

Cu2+(aq)+2e−→Cu(s)(2)(2)Cu2+(aq)+2e−→Cu(s)

As a result, the solution containing Zn(s)Zn(s) becomes more positively charged as the solution containing Cu(s)Cu(s) becomes more negatively charged. For the voltaic cell to work, the Solutions in the two half-cells must remain electrically neutral. Therefore, a salt bridge containing KNO3 is added to keep the Solutions neutral by adding NO3-, an anion, into the anode Solution and K+K+, a cation, into the cathode Solution. As oxidation and reduction proceed, ions from the salt bridge migrate to prevent charge build-up in the cell compartments.

1st most common battery in the field is Lead-acid battery

• Lead is a toxic metal that can enter the body by inhalation of lead dust or ingestion when touching the mouth with lead-contaminated hands. If leaked onto the ground, acid and lead particles contaminate the soil and become airborne when dry.
• The sulfuric acid in a lead-acid battery is highly corrosive and is more harmful than acids used in most other battery systems. Contact with an eye can cause permanent blindness; swallowing damages internal organs that can lead to death. First aid treatment calls for flushing the skin for 10–15 minutes with large amounts of water to cool the affected tissue and to prevent secondary damage. Immediately remove contaminated clothing and thoroughly wash the underlying skin. Always wear protective equipment when handling sulfuric acid.
• Over-charging a lead-acid battery can produce hydrogen sulphide. The gas is colourless, very poisonous, flammable and has the odour of rotten eggs. Hydrogen sulphide also occurs naturally during the breakdown of organic matter in swamps and sewers; it is present in volcanic gases, natural gas and some well waters. Being heavier than air, the gas accumulates at the bottom of poorly ventilated spaces. Although noticeable at first, the sense of smell deadens the sensation with time, and potential victims may be unaware of its presence. As a simple guideline, hydrogen sulphide becomes harmful to human life if the odour is noticeable. Turn off the charger, vent the facility and stay outside until the odour disappears. 

2nd Most common battery in the field is Lithium-Ion battery. 

The three primary functional components of a lithium-ion battery are the positive and negative electrodes and electrolyte:

• The negative electrode of a conventional lithium-ion cell is made from carbon. The most commercially popular anode (negative electrode) is graphite.
• The positive electrode is typically a metal oxide. The positive electrode is generally one of three materials: a layered oxide (such as lithium cobalt oxide), a polyanion (such as lithium iron phosphate) or a spinel (such as lithium manganese oxide).
• The electrolyte is a lithium salt in an organic solvent. The electrochemical roles of the electrodes reverse between anode and cathode, depending on the direction of current flow through the cell. The electrolyte is typically a mixture of organic carbonates such as ethylene carbonate or diethyl carbonate containing complexes of lithium ions. These non-aqueous electrolytes generally use non-coordinating anion salts such as lithium hexafluorophosphate (LiPF) or lithium hexafluoroarsenate monohydrate (LiAsF).
• The positively charged cathode and the negatively charged anode—separated by a thin sheet of "microperforated" plastic that keeps the two electrodes from touching. 

Reaction - During discharge, lithium ions (Li+) carry the current within the battery from the negative to the positive electrode, through the non-aqueous electrolyte and separator diaphragm. During charging, an external electrical power source (the charging circuit) applies an over-voltage (a higher voltage than the battery produces, of the same polarity), forcing a charging current to flow within the battery from the positive to the negative electrode, i.e. in the reverse direction of a discharge current under normal conditions. The lithium ions then migrate from the positive to the negative electrode, where they become embedded in the porous electrode material in a process known as intercalation.

Energy losses arising from electrical contact resistance at interfaces between electrode layers and at contacts with current-collectors can be as high as 20% of the entire energy flow of batteries under typical operating conditions.[128]

Observe - Depending on materials choices, the voltage, energy density, life, and safety of a lithium-ion battery can change dramatically: 

• The current effort has been exploring the use of novel architectures using nanotechnology have been employed to improve performance. Areas on interest include nano-scale electrode materials and alternative electrode structures.
• Pure lithium is highly reactive. It reacts vigorously with water to form lithium hydroxide (LiOH) and hydrogen gas. Thus, a non-aqueous electrolyte is typically used, and a sealed container rigidly excludes moisture from the battery pack.
• Heat is a killer of all batteries, but high temperatures cannot always be avoided. This is the case with a battery inside a laptop, a starter battery under the hood of a car and stationary batteries in a tin shelter under the hot sun. As a guideline, each 8°C rise in temperature cuts the life of a sealed lead acid battery in half. This means that a VRLA battery for stationary applications specified to last for 10 years at 25°C would only live 5 years if continuously exposed to 33°C and 30 months if kept at a constant desert temperature of 41°C. Once the battery is damaged by heat, the capacity cannot be restored. 

Future - In the next five years, the usage of lithium batteries will further expand to heavy-duty platforms, such as military vehicles, boats, shelter applications, aircraft, and missiles. Change is due to several factors:

• Price is expected to decrease to less than $100 / kWh in 2022.
• The new generation of lightweight Li-Ion batteries is much more potent than traditional lead-acid batteries offering unparalleled advantages to advanced armed forces.
• A superior energy density by a factor of 3, coupled with a maintenance-free lithium battery with a 10-year lifetime, will significantly reduce the expensive field logistics of current vehicle batteries.
• A typical NATO dismounted soldier fighting in 2004 in Iraq consumed approximately 500Wh during a 72-hour mission. 2017 high-tech dismounted soldiers consume twice as much.
• Also, military vehicles serve as a stronghold and storage place for dismounted infantry, resupplying their water, food, ammunition, and energy needs. As a result, today's Infantry Combat Vehicles require triple the amount of energy than their lead-acid batteries can store. Adding additional lead/acid batteries is not a feasible alternative as the volume allocated to batteries is restricted.

A typical 8*8 ICV or Main Battle Tank has between eight to ten 6T lead-acid batteries, with the capability to store about 11-14 kWh of energy. This is barely enough to enable the vehicle to perform a 4 to 5-hour silent watch mission, while a typical Middle Eastern night lasts 10 to 14 hours from darkness to dawn.

Why things happen in the field

In order to operate and remain silent, such a vehicle cannot turn on its engine for several hours. A lithium-ion onboard battery with a much higher energy density than the incumbent Lead-Acid will substantially extend the hours of a silent watch from 4 hours to at least 12 hours.

• For comparison, a flooded/AGM 12V 6T battery provides a capacity of 80 Ah (at 1-hour discharge rate) and 0.94 kWh, while new Li-ion 6T batteries offer 165 Ah and 4.18 kWh in similar conditions. 
• A ruggedised NPS 160 battery block will store 4.1 kW and weight only 50 kg. 
• Thermal Runaway and Multiple Cells: While not relevant to single-cell batteries like those found in most smartphones (the iPhone X has two cells), only one battery cell needs to fail for the whole battery to go. Once one cell overheats, you get a domino effect called "thermal runaway." For batteries with hundreds of cells—like those in the Tesla Model S—thermal runaway has the potential to be a huge problem. 

Failure of battery concerning operating temperature

Lithium cells ideal working temperature varies from +15 to +50 Centigrade. Outside of this ideal working temperature, the cycle life will be much shorter. 

A lead-Acid battery will last much longer at +15 Centigrade than in lower or higher temperatures. 

Puzzles, exercises, and fieldwork

1. Why Lead-Acid battery suffers from high temperatures?
2. Explain what are the possible reactions and why, when the vehicle that your crew is mounted gets hit, and the vehicle has either a) Lead-Acid batteries or b) Li-ion batteries onboard?

a. A lead-Acid battery may explode since during operation and charging. Lead-acid batteries produce hydrogen and oxygen which occupies the headspace in a battery above the electrolyte. If such gasses are not vented correctly or are exposed to a source of ignition, battery explosion can occur. In order for a battery to explode, two elements must be present – explosive gasses, namely hydrogen and oxygen, plus a source of ignition, external or originating from within the battery. 

b. Li-ion battery will burn 20-30 minutes, and possibly explode because of short-circuiting as the projectile destroys the plastic separation between anode and cathode.

3. What may happen and why if your crewmate is a) exposed to the electrolyte from a Lead-acid battery, b) titrating or filling electrolyte to Lead-acid batteries?

a. Can cause burns. PVC or other suitable hand protection, eye and face protection and protective clothing must be worn. Dyke and neutralise spills with soda ash or another suitable alkali.

b. Always add concentrated acid to water, never water to acid. Store electrolyte in plastic containers with sealed cover. Do not store in the sun. 

4. Fieldwork: Titrate the right solution for a catalyst from acid and distilled water

1.2 Gas and pressure

Aim: Officers understand the nature of gases. How to measure gas pressure, what happens when gas is heating up or releases energy. 

Orientation

The air pressure is essential for human survivability: 

• The F-16 can climb over 50 000 feet (15 km) and reaches 1 500 mph speed (Mach 2). The air pressure at that height is less than 10 kPa, and human will pass out around when the pressure drops below 57% from normal. 
• Drivers that go deeper than 30 meters are prone to nitrogen narcosis and below 60 meters exposes the diver to oxygen toxicity.
• Soldiers operating over 2 500-meter altitudes will suffer from altitude sickness.

Theory

Pressure - atmospheric & subsurface: The pressure of a gas is the force it exerts on a unit surface area. The pressure is measured with a barometer. (Moore, 2004)The air around you has weight, and it presses against everything it touches.  That pressure is called atmospheric pressure, or air pressure. It is the force exerted on a surface by the air above it as gravity pulls it to Earth. Atmospheric pressure drops as altitude increases. As the pressure decreases, the amount of oxygen available to breathe also decreases. At very high altitudes, atmospheric pressure and available oxygen get so low that people can become sick and even die. Mountain climbers use bottled oxygen when they ascend very high peaks. They also take time to get used to the altitude because quickly moving from higher pressure to lower pressure can cause decompression sickness. Decompression sickness also called "the bends", is a problem for scuba divers who come to the surface too quickly.

An atmosphere (atm) is a unit of measurement equal to the average air pressure at sea level at a temperature of 15 degrees Celsius (59 degrees Fahrenheit). One atmosphere is 1,013 millibars, 101.325 kPa, or 760 millimetres (29.92 inches) of mercury.

At low altitudes above sea level, the pressure decreases by about 1.2 kPa (12 hPa) for every 100 metres.

A diver 10.3 m underwater experiences a pressure of about 2 atmospheres (1 atm of air plus 1 atm of water). Conversely, 10.3 m is the maximum height to which water can be raised using suction under standard atmospheric conditions. 

Pure water boils at 100 °C (212 °F) at Earth's standard atmospheric pressure. The boiling point is the temperature at which the vapour pressure is equal to the atmospheric pressure around the water.  Because of this, the boiling point of water is lower at lower pressure and higher at higher pressure.

Why things happen in the field

The regulator supplies the pilot with breathable air (a mixture of oxygen and nitrogen, the ratio between the two depending on altitude) or 100% oxygen for emergency scenarios. It can also provide a function called partial-pressure breathing for G (PPG), which pushes high-pressure air into your lungs during high-g manoeuvres, which increases g tolerance. 

Combat divers need to know the effects of breathing 100 per cent oxygen at depth, recognise the signs and symptoms of oxygen toxicity, and be able to respond to medical issues that might occur underwater. 

Puzzles, exercises, and fieldwork

1. If a plane flies at 5 000 feet and it loses the created atmosphere inside the chassis, what is the surrounding atmosphere and what may it do to a human?
2. A diver blows a buoy balloon of 20 cm diameter at 50 meters deep, how large it will become when surfacing?
3. A mountain patrol camps at 2000 meters high. What is the boiling temperature of normal water at that height?

2. Protection

Exercises have shown that conventional combat effectiveness can be decreased by 25 per cent or more for military forces compelled to operate in masks, protective overgarments, special gloves, and boots. This is especially true if temperatures are high and forces are required to stay sealed in their gear for many hours or days without relief. Prolonged wearing of personal protective equipment can lead to stress, fatigue, disorientation, confusion, frustration, and irritability. Also, heat can build up and lead to dehydration. Thus, there is generally a trade-off between protecting one's force through chemical-protection gear and maintaining conventional fighting effectiveness.  

2.1 Toxic agents

Aim: Officers shall understand the ways commonly used toxic agents affect human and be able to guide their teams to protect from them.

Orientation

Some known incidents indicating the evolution of insurgents preparing or applying toxic agents: 

Year	Group	Aim
2001	Al-Qaeda, Afghanistan	Testing hydrogen cyanide on animals
2005	Al-Qaeda, Afghanistan	A planned chemical attack on the New York City Subway
2007	Al-Qaeda, Iraq	15 vehicle bombs with chlorine tanks, 115 killed, 854 injured
2012	Terrorists Afghanistan	Used pesticides to attack school children, 1952 injured
2013	Syrian military	Sarin rockets used around Damascus to kill 1429 and injured over 2200
2014	Syrian military	Chlorine bombs used against urban inhabitants
2016	ISIS, Iraq	Activated a sulphur mine near Mosul producing sulphur dioxide, 2 killed, 1500 injured

Plant Toxins

The vegetable kingdom offers a great variety of substances with many biological activities, which are typically produced as final products of the metabolism. Secondary metabolites with considerable toxic effects include terpenes, glycosides, alkaloids, amines, phenols, and other organic compounds. Plant toxins, as we have seen, serve as a basis of arrow poisons and they have long been used as parts of different tactical warfare mixtures. Some of them were recently subjected to military research. For example, the alkaloid physostigmine, isolated from the species Physostigma venenosum, served as a comparative standard in the development of synthetic inhibitors of acetylcholinesterase (AChE) or possibly in the development of protecting means against them. A less numerous but important group of metabolites in terms of their military use are toxic proteins. The full attention is focused on ricin or possibly abrin, modeccin (Adenia digitata), viscumin (Viscum album) or volkensin (Adenia volkensii), which have a similar structure, similar mechanism of toxic action (inhibition of protein synthesis), and almost identical clinical course of intoxication.

LD50 values (mouse, i.v.) for ricin are lower by a factor of five compared to V.X. and lower by a factor of more than 30 compared to Sarin. Even though the lethal inhalation dose of ricin for humans is at the level of Sarin, the protection from ricin aerosol in the form of powder or solutions does not pose special difficulties. Pure ricin is readily soluble in water only, which is frozen at low temperatures. The suspension of ricin in tetrachloromethane (filling of experimental bombs) is unstable and affects the ballistic parameters of the ammunition. All forms of ricin are susceptible to ultraviolet radiation, and thus its use in combat is problematic in periods of high solar activity. A certain handicap of ricin is also its slow action (toxic effect occurs after 8 to 72 h), which excludes operational-tactical use under the conditions of modern mobile combats. These disadvantages of ricin are not outweighed even by its easy preparation. 

Animal Toxins

An important source of protein, as well as non-protein toxins exerting a variety of toxic effects, is also the animal kingdom. Certain poisonous animals have a special organ (gland) producing toxins (for example snakes, spiders, scorpions or a group of actively poisonous sea animals), some others do not have such an organ, and their toxins are products of their metabolism or possibly parts of the biochemical structure of certain body parts. A proportion of animals acquire toxins from their environment (for example, from their food) and the toxins are subsequently accumulated in their bodies. The military use of animal toxins is limited compared to plant toxins because there are usually problems with their manufacture on a large scale. However, this handicap is gradually overcome due to the development of new methods of chemical synthesis and biotechnology [34,35]. Animal toxins, which can be of interest for military use due to their high toxicity, include batrachotoxin, epibatidine, zetekitoxin A.B. and other alkaloids from the skin secretions of frogs from the families Dendrobatidae and Bufonidae, some active components of snake venoms such as taipoxin (Oxyuranus scutallatus), bungarotoxin (Bungarus multicinctus), and α-cobratoxin (Naja siamensis), spider toxins, for example, α-latrotoxin isolated from the species Latrodectus mactans, and other toxins of terrestrial animals. 

Marine Toxins

An interesting group of toxins are those of marine origin produced by toxicogenic algae, cyanobacteria, and bacteria, which are common food of marine animals (certain species of fish, crustaceans, and molluscs), in which they are deposited (due to this, they are sometimes considered as animal toxins). These are non-protein substances, inducing alimentary poisoning in man and animals with different syndromes: paralytic shellfish poisoning (PSP), neurotoxic shellfish poisoning (NSP), amnesic shellfish poisoning (ASP), diarrheic shellfish poisoning (DSP), ciguatera fish poisoning (CFP) and azaspiracid shellfish poisoning (ASP) [36]. Neurotoxins represent the highest risk with specific effects on the nervous system (saxitoxin, tetrodotoxin, palytoxin, maitotoxin, α-conotoxin, and others), which also exert a considerable military potential. 

Bacterial Toxins

Protein toxins produced by microorganisms induce several bacterial diseases (for example, diphtheria, botulism, tetanus). Their biochemical structure is considerably diverse; they can be in the form of simple chains or substances comprising several units. Based on the chemical composition, thermostability, and method of release as a pathogen, bacterial toxins can be divided into two groups: exotoxin (toxic bacterial proteins) and endotoxins (toxic lipopolysaccharides) [33]. Exotoxins, which are considerably more toxic than endotoxins, are released by bacterial cells into the surrounding environment; endotoxins are, in contrast, bound to the cell wall of gram-negative bacteria. Certain exotoxins (for example, diphtheric) are released from the bacterial cell in the form of non-active protoxin, which is subsequently activated by proteolytic splitting [30]. Depending on their mechanism of action, bacterial toxins can be divided into toxins damaging membranes (for example α-toxin), toxins inhibiting protein synthesis (for example shiga toxin), toxins activating second messenger pathways (for example cholera toxin), activators of an immune response (for example staphylococcal enterotoxins), and proteolytic toxins (for example botulinum toxin, tetanus toxin) [38]. In experiments on animals, the lowest LD50 values are found in botulinum toxin and tetanus toxin, which have similar structures (belonging to the most complex known toxins), enzymatic activity, as well as effects on cells of the nervous system. 

Mycotoxins

Microscopic and macroscopic fungi also produce toxins. Particularly mycotoxins, low-molecular-weight secondary metabolites of microscopic fungi that are responsible for various mass food poisonings (mycotoxicoses) can also be of importance from the viewpoint of military applications. The advantage of mycotoxins is the ease of their production on a large scale (by cultivation techniques or by synthetic methods) and their generally high stability (they are resistant to boiling). However, the existing military experience with several mycotoxins cannot be directly applied to the whole group of mycotoxins, since they have different chemical structures, biological characteristics, and effects (cytotoxic, neurotoxic, immunosuppressive, etc.). 

Neurotoxins attack the nervous system and can cause a myriad of conditions, including convulsions, neuropathy, paralysis, stopped breathing, loss of mental capacity, loss of muscle control, coma, death, and congenital disabilities. Neurotoxins include pesticides and related compounds that are commonly misused because they are widely found in homes and agriculture.

 

Why things happen in the field

Terrorists using toxins:

1. For example, in 1980, the West-German terrorist group Red Army Faction was suspected of having planned using botulinum toxin, which was prepared in a private laboratory in Paris. 
2. This kind of toxin was also used for experiments by the Japanese faction Aum Shinrikyo, known mainly for their sarin attack in the Tokyo metro 1995. 11 bags with 600 g each of Sarin were released on 3 main subway lines in Tokyo, resulting in 12 deaths and nearly 4,000 injuries.
1. Sarin is an organophosphorus compound developed by Germany in 1938 as a pesticide. It is a potent nerve agent because it is a strong acetylcholinesterase inhibitor that degrades the neurotransmitter acetylcholine. It has an LD50 of 660 ug/kg (oral, rat) and is a colourless, odourless, tasteless liquid. In humans, it is about 26 times as deadly as cyanide gas. With a vapour pressure of 2.9 mm Hg @ 25oC and volatility of 22,000 mg/m3@ 25oC it can evaporate readily and spread into the environment. 
3. The American nationalist anti-governmental movement Minnesota Patriots Council planned the use of ricin in dimethyl sulfoxide solution (with an admixture of extract from the plant Aloe vera) or the form of dry aerosol in 1991. 
4. In the course of the Chechnya war (2001), Russian authorities revealed a plan of local rebels who reportedly intended to use ricin in the form of mixed ammunition. 

The use of toxins for terrorist purposes is less probable than the use of harmful industrial substances or classic CWA, but the probability is higher than for military use. There are questions about their actual effects: 

• Ricin, as well as other known toxins, are relatively quickly accessible to any qualified specialist. However, their use in terrorist attacks to induce mass intoxications through inhalation is problematic. This reduces the probability of inhalation attacks. 
• Terrorist attacks focused on drinking water and food sources, and particularly on the destruction of a particular person or group are more realistic. 
• At the time of current information, technologies, and propagation of the fear of a global threat by weapons of mass destruction, toxins can serve as an efficient psychological weapon, even if they are not used.

Puzzles, exercises, and fieldwork

1. Why is ricin easy to produce?
2. What attack vectors the terrorists and insurgent would most probably use if they are after maximum impact at a physical level?
3. Why and how terrorist may use toxins to optimise the terror at information and cognitive levels?

3. Manoeuvre

Armed Forces are simplifying their logistics and minimising the failures of wrong fuel by providing a single-fuel concept that mixes aviation kerosene with diesel fuel. Both turbine-powered and diesel engines should burn the same fuel without problems. NATO F65 mixture includes 50/50 of the before mentioned.

3.1 Fuels and releasing energy by burning

Aim: Officers understand the chemical reaction behind the fundamental sources of energy in the field and vehicles.

Fossil fuels

Chemical energy is released typically in the reaction of oxidation. Raw oil consists of hydrocarbons (C.H.).  In a refinery, Pentane and Octane will be refined into gasoline, hexadecane and nonane will be refined into kerosene or diesel or used as a component in the production of jet fuel, hexadecane will be refined into fuel oil or heating oil. 

Separation of different fractions of hydrocarbons happens in distillation. Different boiling points separate different fractions. 

Burning to release energy

In an ideal situation, a combustion engine burns petroleum creating carbon dioxide, water, and heat energy.

2 CnH2n+2 (g) + (3n+1) O2(g) = 2nCo2(g) + 2(n+1)H2O (g) + heat energy (Moore, 2004)

If oxygen is limited, then the carbon and oxygen does not meet fully, but carbon monoxide is created. Here a simple methane molecule is burned: 

CH4 + 2 O2 (g) = 2 H2O + CO2 + CO + Energy 

If engine is running idle, it may not have enough air intake, therefore C.O. is created more. 

Fuel cells  

A fuel cell (Chan & Tan, 2015) is a device that uses fuel to react with oxygen in the air to produce electrical energy directly. The oxidising agent is oxygen gas which is supplied to the cathode (positive) compartment. The fuel (hydrazine H2N-NH2, methanol CH3OH or sugar C6H12O6) is fed to the anode (negative) compartment. The electrodes are from platinum or palladium. The electrolyte may be NaOH or H2SO4. In the reaction, 2H2 gas molecules combine with O2 molecule, and the outcome of the reaction is water H2O, electrons that flow from anode to cathode and excess heat.

Variety of petroleum products used in the battlefield 

Product	Description	Use	NATO/US code
Gasoline	A military fuel used in specific armoured and non-armoured vehicle spark-ignition engines in NATO Europe areas outside Denmark and the United Kingdom, also known as gasoline automotive: Military (91 RON) or COMBATGAS.		F-46
	Low leaded gasoline introduced to replace F-46. It is interchangeable with commercial gasoline automotive (98 RON).		F-57
Diesel	A military fuel used in compression ignition engines in NATO. Also known as Diesel Fuel: MILITARY or DF-2.	It has a Pour Point specification of 18 Centigrade maximum.	F-54
	Low-temperature diesel/kerosene fuel blend.		F-65
Kerosene	A military kerosene-type aviation turbine fuel with Fuel System Icing Inhibitor (FSII). Also known as JP-8 or AVTUR/FSII. JET A-1 or AVTUR + Additives (NOTE 3) = JP-8 or AVTUR/FSII.	They are used by land-based military gas turbine engined aircraft in all NATO countries. Freezing point -46C	F-34
	A military kerosene-type aviation turbine fuel. Also known as JET A-1 or AVTUR. JET A-1 or AVTUR. Aromatics typical of cracked gasoline and kerosene include benzene, alkylbenzenes, toluene, xylene, indenes, naphthalenes. [1]	equivalent to that used by most civil operators of gas turbine engined aircraft	F-35
Naval fuels	A naval fuel used in compression ignition engines and also known as FUEL, NAVAL DISTILLATE, low pour point. Composition:[2] C9–C20 paraffins, vol % ≈ 13%; aromatics, vol % ≈ 44%; naphthalenes, vol % ≈ 44%; may contain some (< 10%) polycyclic aromatic hydrocarbon.	Used also in naval gas turbines and ships' boilers for steam raising.	F-75
	Primary naval fuel used as for F-75 above, but it may require special handling and storage due to low-temperature characteristics.		F-76

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[1] https://www.globalsecurity.org/military/systems/aircraft/systems/engines-fuel.htm

[2] https://www.ncbi.nlm.nih.gov/books/NBK231234/

Puzzles, exercises, and fieldwork

1. What is the source for the energy, when burning fossil fuel?
2. Why is the combustion engine exhaust toxic?
3. Why is it challenging for the military to use fuel cells widely in creating electricity in the operations?
4. Explain the differences between gasoline, diesel and kerosene in military use
5. Why may a fuel tank explode when hit with a kinetic warhead?

3.2 Propellants and propulsion 

Aim: Officers understand the chemical reaction behind military propellants and propulsion. They can identify different ways of propelling military projectiles.

Orientation

Platoon is in the shooting range with CAR 816  assault rifles. One of the platoon members wonders how the rifle works in automatic mode. How does the Platoon leader explain the gas-operated reloading?

Theory

The military propellant is a chemical used in the production of energy or pressurised gas that is subsequently used to create a movement of a fluid or to generate propulsion of a vehicle, projectile, or another object. Common propellants are energetic materials and consist of fuel like gasoline, jet fuel, rocket fuel, and an oxidiser. Propellants are burned or otherwise decomposed to produce the propellant gas. Other propellants are simply liquids that can readily be vaporised.

In rockets and aircraft, propellants are used to produce a gas that can be directed through a nozzle, thereby producing thrust. In rockets, rocket propellant produces an exhaust, and the exhausted material is usually expelled under pressure through a nozzle. The pressure may be from compressed gas or a gas produced by a chemical reaction. The exhaust material may be a gas, liquid, plasma, or, before the chemical reaction, a solid, liquid, or gel. In aircraft, the propellant is usually a fuel and is combusted with the air.

In firearm ballistics, propellants fill the interior of an ammunition cartridge or the chamber of a gun or cannon, leading to the expulsion of a bullet or shell (gunpowder, smokeless powder, and extensive gun propellants). Explosives can be placed in a sealed tube and act as a deflagrant low explosive charge in mining and demolition, to produce a low-velocity heave effect (gas pressure blasting).

The primary component of a gun, artillery, and mortar propellant formulations is commonly a nitro-containing organic chemical such as nitrocellulose (N.C.) often combined with other energetic compounds such as nitroglycerin (N.G.), nitroguanidine (N.Q.), or dinitrotoluenes (DNT). 2,4-Dinitrotoluene (DNT) is used in the production of smokeless powders, as a plasticiser in rocket propellants and as a gelatinising and waterproofing agent. 

Propellant	Definition	Use
M1	Composed of 85 % nitrocellulose, 10 % 2,4-DNT, approximately 5 % dibutlyphtalate and 1 % potassium sulphate.	Since II WW as cannon munition
M3A1[1]	The entire M3A1 propellant contains approximately 5.5 pounds of single perforated neutral burning powder. There are flash reducers containing potassium sulfate or potassium nitrate sewn forward of charges.  The flash reducers limit breech flare back, muzzle flash, and blast overpressure.	US 155mm artillery propelling charges

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[1] https://www.globalsecurity.org/military/systems/munitions/155-prop.htm

Puzzles, exercises, and fieldwork

1. What is the source for the energy, when blasting an artillery charge?
2. Why does an assault rifle work when switched automation?
3. How does a rocket work?
4. How does a missile work?

3.4 Essential chemistry for a human to move

Aim: Officers understand the chemical reaction of human oxygen consumption and carbon dioxide extraction. They can detect the typical symptoms of breathing-related failures and launch remedy.

Orientation

Platoon is transported on a C-17 plane which is flying at 28 000 feet. Suddenly, the aircraft loses its internal pressure. What the platoon leader should anticipate happening and how to mitigate the reactions of platoon members?

Theory

Once oxygen has entered the blood from the lungs, it is taken up by haemoglobin (Hb) in the red blood cells. Haemoglobin is a protein that is made up of four haem groups, which contain iron ions. These iron ions (Fe2+) associated with haemoglobin molecules chemically react with oxygen to form oxyhaemoglobin. 

Each molecule of haemoglobin can hold four oxygen molecules. It is haemoglobin that carries the oxygen as it is transported around the body in the blood. Only a small amount of oxygen (1.5% in arterial blood) is simply dissolved in the plasma.

Hb(aq) + 4O2 = Hb(O2)4 (aq) (Curtis, et al., 2018)

As long as there is sufficient oxygen in the air, a healthy equilibrium is maintained. If the concentration of air is less or it is replaced with carbon monoxide, the equilibrium shifts to the left.

Hb(aq) + 4CO = Hb(CO)4 (aq) (Curtis, et al., 2018)

Carbon monoxide has a greater affinity for haemoglobin than does oxygen. Therefore, when carbon monoxide is present, it binds to haemoglobin preferentially over oxygen. As a result, oxygen cannot bind to haemoglobin, so truly little oxygen is transported throughout the body. Carbon monoxide is a colourless, odourless gas which is difficult to detect. It is produced by gas-powered vehicles and tools. Carbon monoxide can cause headaches, confusion, and nausea; long-term exposure can cause brain damage or death. Administering 100 per cent (pure) oxygen is the usual treatment for carbon monoxide poisoning as it speeds up the separation of carbon monoxide from haemoglobin. 

Hb(CO)4 (aq) + 4O2 (g) = Hb(O2)4 (aq) + 4CO (g) (Curtis, et al., 2018)

Why things happen in the field

Altitude sickness 

The pressure of the air that surrounds you is called barometric pressure. When you go to higher altitudes, this pressure drops, and there is less oxygen available. If you live in a place that is located at a moderately high altitude, you get used to the air pressure. However, if you travel to a place at a higher altitude than you are used to, your body will need time to adjust to the change in pressure. Any time you go above 8,000 feet, you can be at risk for altitude sickness.

Symptoms usually come on within 12 to 24 hours of reaching a higher elevation and then get better within a day or two as your body adjusts to the change in altitude. If you get a headache and at least one other symptom associated with altitude sickness within a day or two of changing your elevation, you might have altitude sickness. If your symptoms are more severe, you will need medical attention. The best way you can lower your chance of getting altitude sickness is through acclimatisation. That means you let your body slowly get used to the changes in air pressure as you travel to higher elevations.

Carbon monoxide poisoning 

Carbon monoxide (C.O.) poisoning occurs when carbon monoxide builds up in your bloodstream. When too much carbon monoxide is in the air, your body replaces the oxygen in your red blood cells with carbon monoxide. This can lead to severe tissue damage or even death. Carbon monoxide is a colourless, odourless, tasteless gas produced by burning gasoline, wood, propane, charcoal, or other fuel. Improperly ventilated appliances and engines, particularly in a tightly sealed or enclosed space, may allow carbon monoxide to accumulate to dangerous levels.

Keep your fuel-burning appliances and engines properly vented. Use caution when working with solvents in a closed area. Methylene chloride, a solvent commonly found in paint and varnish removers, can break down (metabolise) into carbon monoxide when inhaled. Exposure to methylene chloride can cause carbon monoxide poisoning.

Puzzles, exercises, and fieldwork

1. Your BMP-3 vehicle is positioned for battlefield observation. You are using the engine to run electronics and keeping the crew more comfortable, but you also have the bottom latch open if you are caught by surprise. After a few hours, your crew starts complaining of headache and dizziness. What may cause it?
2. You are flying over 10 000 feet, and you feel dizziness, sleepy and disoriented. What may be the cause and how to retain your normal physical abilities?

4. Fires and Effects

A Platoon is taking a break between shooting exercises in a range. One of the soldiers wonders what happens when a bullet hits the armour. Soon others join in the conversation and start arguing why some bullets penetrate armour, and some do not. As a platoon leader, you are expected to provide your troops with a rational explanation.

4.1 Transfer of forms at molecule and atom level

Aim: Officers understand the chemical reactions happening in kinetic impact.

Theory

When a bullet hits protective material,  the energy of the bullet starts changing the molecular structure of the protective material. The density (hardness) of each material will define the penetration as well as other energy absorption features of protection.  Density is expressed in grams per centimetre cubed (g/cm 3 or gm · cm-3). Pure liquid water at a temperature of 4 degrees Celsius has a density of 1 g/cm 3, which is the equivalent of 1 kg per 1000 cm 3, or 1 kilogram per litre. To convert from kg/m 3 to g/cm 3, multiply by 0.001.

Conversely, to convert from g/cm 3 to kg/m 3, multiply by 1000.  

The density of material depends on microstructure evolution under pressure, gas pressure sintering, hot pressing, or hot isostatic pressing. It also depends on the type of additive incorporated during sintering. The features defining material density are, for example: 

• When atom mass is higher, the material is denser
• When atoms are packed closer together, the material is denser (compare the weight of similar cubes of wood and iron). 
• Mixing different molecules (iron with carbon = steel) produces alloys, which are harder to break with kinetic energy. 

Kinetics

For a single particle of mass (m) moves with velocity (v), its kinetic energy (T) is defined as :

T=1/2 mv^2

The faster something moves and the heavier it is, the more momentum it has. Even though bullets are tiny, they have lots of momentum because they go so fast. Moreover, because they go fast, they also have vast amounts of kinetic energy, which they get from the chemical energy of the burning propellant. (Remember that kinetic energy is related to the square of an object's velocity—so if it goes twice as fast, it has four times the energy.)

Bullets do damage when they transfer their energy to the things they hit. The faster something loses its momentum at the target, the more force it produces. (One way to define force is as the rate at which an object's momentum changes.) A rifle bullet coming to a stop in a tenth of a second produces as much force as a massive, slow-moving truck coming to rest in 10 seconds.  

Puzzles, exercises, and fieldwork

1. Explain your platoon what happens when a bullet hits the armour and why it does not penetrate the BMP-3 armour (See also physic exercises for land forces)
2. Why it requires more concrete to protect from a bullet than steel?
3. Why is steel better armour than pure iron?

4.2 Bullet, prime and propellants

Aim: Officers understand the chemical reactions taking place when a cartridge is fired.

Theory

A cartridge is a three-part vehicle with the actual bullet mounted on the very end. The cartridge is the thing you load into a rifle; the bullet is the part of a cartridge that fires out the end. Cartridges are arranged in three sections: the primer, the propellant, and the bullet proper.  

At the back, the primer (or percussion cap) is like the fuse of a firework: a small fire that starts a bigger one. The next section of the cartridge, effectively the bullet's "main engine," is a chemical explosive called a propellant. The double-base smokeless charge is nitrocellulose, a polymer that gives body to the powder and allows extrudability. The addition of nitro-glycerine softens the propellant, raises the energy content and reduces hygroscopicity. Adding nitroguanidine reduces flame temperature, embrittles the mixture at high concentration, and improves energy-flame temperature relationship.  The propellant powers the bullet down the gun and through the air to the target. The front part of the cartridge is the actual bullet: a tapering metal cylinder that hits the target at high speed. 

When you pull the trigger of a gun, a spring mechanism hammers a metal firing pin into the back end of the cartridge, igniting the small explosive charge in the primer. The primer then ignites the propellant—the main explosive that occupies about two-thirds of a typical cartridge's volume. As the propellant chemicals burn, they generate lots of gas very quickly. The sudden, high pressure of the gas splits the bullet from the end of the cartridge, forcing it down the gun barrel at high speed. NATO 7.62x51 mm cartridge has 2756 J energy and velocity of 823 m/s at 24 meters.

Puzzles, exercises, and fieldwork

1. What propels the bullet out from the rifle barrel?
2. Why is it essential to accelerate the speed of a bullet to its realistic maximum?
3. What energy is used to make a gun automatic?

4.3 Explosives 

Aim: Officers understand the fundamental chemical reaction of the military explosion.

Theory

Commonly used military energetic compounds include the explosives 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). They all include nitrogen as flammable and oxygen to create fast-burning reaction, i.e. blast. 

N2 + O2 --> 2NO - 43,200 calories 

Nitroglycerin (N.G.), nitroguanidine (N.Q.), nitrocellulose (N.C.), 2,4-dinitrotoluene (DNT). Chemical structure of 2,4,6-trinitrotoluene in Figure.

TNT is popular in the military and industry because of its insensitivity to shock and friction, which reduces the risk of accidental detonation. The TNT molecule is slightly soluble in water and has a low vapour pressure. In humans, TNT is associated with abnormal liver function and anaemia, and both TNT and RDX have been classified as potential human carcinogens. 

Evolution of explosives -video. https://www.youtube.com/watch?v=c3DM_TeKwfg

Chemical explosives are categorised into two classes:

1. Low explosives are typically employed as propellants. They undergo auto combustion at rates that vary from a few centimetres per second to approximately 400 meters per second. Included in this group are smokeless powders and pyrotechnics such as flares and illumination devices.
2. High explosives are usually employed in warheads. They undergo detonation at rates of 1,000 to 8,500 meters per second. High explosives are conventionally subdivided into two classes and differentiated by sensitivity:
1. Primary. These are extremely sensitive to shock, friction, and heat. They will burn rapidly or detonate if ignited.
2. Secondary. These are relatively insensitive to shock, friction, and heat. They may burn when ignited in small, unconfined quantities; detonation occurs otherwise.

Puzzles, exercises, and fieldwork

1. Why do military explosives need to be insensitive to shock, friction or heat? Why not just use nitro-glycerine?
2. How military ordnance is structured to maximise the controlled detonation but prevents the uncontrolled blasts?
3. Explain to your team how TNT reacts when it is ignited
4. Why is oxygen packed in military explosives? Why is it not enough to use O2 of the air?

4.4 Pyrotechnics

Aim: Officers understand the chemical reactions behind major military pyrotechnics, know their effect on health and can use them safely.

Theory

Traditionally pyrotechnics have been made from the fuel and oxidant in the form of finely-divided powders. Fuels have ranged from metals, such as aluminium, magnesium and iron, to non-metals, such as silicon, carbon, sulphur, and some organic compounds. Oxidants have included oxides, peroxides and oxysalts. Various additives may be included to promote particular properties essential to the manufacture or application of the pyrotechnics. Of more recent origin has been the development of bimetallic alloying pyrotechnics and the use of resin-bonded and polymeric materials. 

Type	Explanation
Smokes	Conventional white smokes contain zinc and hexachloroethane, which form chlorides and oxides of zinc as reaction products; both of these are highly toxic. [1]   Obscurants, such as phosphorus smokes, are effective in blocking the transmission of a particular part of the electromagnetic spectrum, such as visible light, infrared light, or microwaves. Military application of phosphorus smokes for screening during a military operation can make use of either white phosphorus (W.P.) or red phosphorus (R.P.). WP is the most effective smoke agent to defeat thermal imagery systems.[2]   In terms of aerosol concentration, it can be assumed that a stable, slow-precipitation smoke has a low weight concentration up to 0.1 g/m3 and a particulate concentration between 105 and 106 particles per 1 cm3.[3] Multispectral smoke screens electromagnetic radiation in the 0.4-12 µm spectrum.
Photoflash Compositions	Photoflash compositions based on magnesium or aluminium and potassium perchlorate (and a flow modifier) have often been used as a sound-producing composition for battle effect simulators and grenades for special forces. They also have application as a spotting charge for mortar rounds, but this requires a higher filling density for efficiency reasons.[4]
Magnesium powder	Magnesium is one of the most common fuels used in pyrotechnic compositions. Although it has a high combustion temperature and large heat of combustion, it suffers from degradation on storage. Moisture readily attacks magnesium powder, generating hydrogen gas which presents a severe problem in sealed stores. The reaction decreases the amount of available magnesium, thus reducing the efficiency and performance of the pyrotechnic composition. These effects are somewhat reduced by coating the magnesium powder with various organic binders, but problems are still known to occur.[5]
Thermites[6]	Iron thermite uses either iron (III) oxide or iron (II, III) oxide. The former produces more heat. The latter is more comfortable to ignite, likely due to the crystal structure of the oxide. Addition of copper or manganese oxides can significantly improve the ease of ignition. The density of prepared thermite is often as low as 0.7 g/cm3. This, in turn, results in relatively low energy density (about 3 kJ/cm3), rapid burn times and spray of molten iron due to the expansion of trapped air. Thermite can be pressed to densities as high as 4.9 g/cm3 (almost 16 kJ/cm3) with slow-burning speeds (about 1 cm/s). Pressed thermite has higher melting power, i.e. it can melt a steel cup where low-density thermite would fail. Iron thermite with or without additives can be pressed into cutting devices that have heat resistant casing and a nozzle. Oxygen balanced iron thermite 2Al + Fe2O3 has a theoretical maximum density of 4.175 g/cm3 an adiabatic burn temperature of 3135 K or 2862 °C or 5183 °F (with phase transitions included, limited by iron which boils at 3135 K), the aluminium oxide is (briefly) molten, and the produced iron is mostly liquid with part of it being in gaseous form - 78.4 g of iron vapour per kg of thermite is produced. The energy content is 945.4 cal/g (3 956 J/g). The energy density is 16 516 J/cm3. Copper thermite can be prepared using either copper(I) oxide (Cu2O, red) or copper (II) oxide (CuO, black). The burn rate tends to be fast, and the melting point of copper is relatively low, so the reaction produces a significant amount of molten copper in a short time. Copper (II) thermite reactions can be so fast that copper thermite can be considered a type of flash powder. An explosion can occur and send a spray of copper drops to a considerable distance. Oxygen balanced mixture has a theoretical maximum density of 5.109 g/cm3, adiabatic flame temperature 2843 K (phase transitions included) with the aluminium oxide being molten and copper in both liquid and gaseous form. 343 g of copper vapour per kg of this thermite is produced. The energy content is 974 cal/g.
Napalm	A combustible mixture of a gelling agent and a volatile petrochemical (usually gasoline (petrol) or diesel fuel). Napalm B uses Polystyrene derivatives as a gelling agent. Napalm burns at temperatures ranging from 800° C (1,472° F) to 1200° C (2192° F). Besides, it burns for a more significant duration than gasoline, as well as being more easily dispersed and sticking tenaciously to its targets. These traits make it extremely useful in the anti-structure and antipersonnel role. Multiple nations (including the United States, China, Russia, Iran, and North Korea) maintain large stockpiles of napalm-based weapons of various types.   Napalm is effective against dug-in enemy personnel. The burning incendiary composition flows into foxholes, trenches and bunkers, and drainage and irrigation ditches and other improvised troop shelters. Even people in undamaged shelters can be killed by hyperthermia, radiant heat, dehydration, asphyxiation, smoke exposure, or carbon monoxide poisoning.   One firebomb released from a low-flying plane can damage an area of 2,500 square yards (2,100 m2). Turkey has been accused of using Napalm in its war against Kurdish militias over Afrin. Turkey's General Staff, however, denies this. Napalm bombs generate carbon monoxide while simultaneously removing oxygen from the air. The air in the bombing area can be 20 per cent or more carbon monoxide.[7]

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[1] https://apps.dtic.mil/dtic/tr/fulltext/u2/a238923.pdf

[2] https://www.ncbi.nlm.nih.gov/books/NBK224560/#:~:text=The%20military%20uses%20smokes%2C%20such,artillery%20shells%20and%20in%20grenades.

[3] file:///C:/Users/User/Downloads/W%20adys%20aw%20Harmata.pdf

[4] https://apps.dtic.mil/dtic/tr/fulltext/u2/a238923.pdf

[5] https://apps.dtic.mil/dtic/tr/fulltext/u2/a238923.pdf

[6] https://en.wikipedia.org/wiki/Thermite#:~:text=The%20addition%20of%20barium%20nitrate,in%20welding%20together%20metal%20components.

[7] https://science.howstuffworks.com/napalm.htm

Why things happen in the field

Observe: 

• Thermite usage is hazardous due to the too high temperatures produced and the extreme difficulty in smothering a reaction once initiated. Small streams of molten iron released in the reaction can travel considerable distances and may melt through metal containers, igniting their contents. Additionally, flammable metals with relatively low boiling points such as zinc (with a boiling point of 907 °C, which is about 1,370 °C below the temperature at which thermite burns) could potentially spray superheated boiling metal violently into the air if near a thermite reaction.
• Mixing water with thermite or pouring water onto burning thermite can cause a steam explosion, spraying hot fragments in all directions.
• If thermite is contaminated with organics, hydrated oxides, and other compounds able to produce gases upon heating or reaction with thermite components, the reaction products may be sprayed.
• Finely powdered thermite can be ignited by a flint spark lighter, as the sparks are burning metal (in this case, the highly reactive rare-earth metals lanthanum and cerium). Therefore, it is unsafe to strike a lighter close to thermite.
• When used as a part of an incendiary weapon, Napalm can cause severe burns (ranging from superficial to subdermal), asphyxiation, unconsciousness, and death. In this implementation, napalm fires can create an atmosphere of greater than 20% carbon monoxide and firestorms with self-perpetuating winds of up to 70 miles per hour (110 km/h).

Puzzles, exercises, and fieldwork

1. How many smoke grenades you need to deploy to create a 10 m wide screen that lasts 60 seconds between you and enemy position? One smoke grenade creates 105 particles/cm3 for 20 seconds in an area of 3 m3.
2. Define the ways to disable your computer hard drives and USB-memories silently if you have to withdraw your staff within 3 minutes and would not be able to carry them with you?
3. Name ways to put down thermite initiated fire.
4. Why Napalm is sticky and why does it burn slower than plain gasoline?
5. You have just requested a low delivered Napalm strike on top of the enemy fortification. Once the bomb has been delivered, what you should consider before entering the strike zone with your platoon?

References

Chan, K. S. & Tan, J., 2015. Understanding basic chemistry through problem solving. Singapore: World Scientific Publishing Co.

Curtis, C., Murgatroyd, J. & Scott, D., 2018. Chemistry student book 1. London: Pearson Education Limited.

Moore, J. T., 2004. Chemistry made simple. 3rd toim. New York: Broadway Books.