Chemistry of Gases and Applications

Champagne and soda get their bubbles from dissolved carbon dioxide (CO2) gas. When pressure is released, the gas comes out of solution, creating bubbles. Hydrogen, nitrogen, and oxygen are not used in carbonation.

All elements can exist in all three states (solid, liquid, gas) given appropriate temperature and pressure conditions. Iron has a boiling point of 2862°C (5184°F), so it can indeed exist as a gas when heated above this temperature. While we typically encounter iron as a solid in everyday conditions, it transitions to liquid and gas phases at extremely high temperatures.

Nitrogen (N2) was named 'Azote' by Antoine Lavoisier, derived from Greek 'a-' (without) and 'zoe' (life), meaning 'lifeless'. This was because nitrogen does not support combustion or respiration. CO2 is carbon dioxide, H2 is hydrogen, and Xe is xenon - none were given this name by Lavoisier.

Nitrous oxide (N2O) is commonly called laughing gas due to its euphoric effects when inhaled. It was discovered in 1772 and has been used as an anesthetic and analgesic in medical and dental procedures for over 150 years.

Sodium is a soft, silvery-white alkali metal in group 1 of the periodic table. Unlike gases or vapours, it exists as a solid metal at room temperature with characteristic metallic properties like electrical conductivity and malleability.

Chlorine gas (Cl₂) has a distinctive greenish-yellow color and is highly toxic. This characteristic coloration is due to its molecular structure and light absorption properties in the visible spectrum. Among halogens, chlorine is easily identified by this pale yellow-green appearance.

Fluorine gas (F₂) is pale yellow-green in color, making 'Green' the closest answer among the options. As the most electronegative and reactive element, fluorine's distinctive coloration comes from its molecular absorption properties in the visible spectrum. The pale green tint is characteristic of all halogen gases.

Hydrogen is highly flammable and burns readily in air to form water. Helium and nitrogen are noble gases that are inert and do not burn. Oxygen supports combustion but is not itself flammable - it is an oxidizer that enables other materials to burn.

Nitroglycerine is a powerful explosive used in mining, construction, and demolition. It is a highly unstable nitrate ester that detonates violently, though in medical applications (nitroglycerin tablets) it's used in very small doses to treat angina. The other options - Phosphorus Trichloride (a chemical reagent), Mercuric oxide (a mercury compound used in batteries), and Graphite (a form of carbon) - are not explosives. Nitroglycerine's explosive properties come from its rapid decomposition releasing large volumes of gas.

Air is a homogeneous mixture of gases (nitrogen, oxygen, argon, CO2, etc.), making it a solution composed entirely of gases. Petroleum is liquid hydrocarbon mixture, soda is liquid with dissolved gas, and Kool-Aid is solid dissolved in liquid.

All elements can exist as gases at sufficiently high temperatures. Iron's boiling point is approximately 2862°C (5184°F). Above this temperature, iron transitions from liquid to gas phase. Phase depends on temperature and pressure - solid, liquid, and gas are just states of matter for the same substance.

The Bhopal gas tragedy of 1984 was caused by methyl isocyanate (MIC) gas leakage from Union Carbide pesticide plant. MIC is highly toxic and caused immediate deaths and long-term health issues. The other options are common gases but not involved in this disaster.

The Bhopal gas tragedy of December 1984 was caused by methyl isocyanate (MIC) gas leaking from a Union Carbide pesticide plant. MIC is highly toxic and used in pesticide production. The disaster killed thousands and injured hundreds of thousands.

TNT (trinitrotoluene) is a yellow, odorless solid in its pure form. The 'trinitrotoluene' in the question appears to be a typo. TNT is an explosive compound that does not occur naturally and must be synthesized. Its characteristic pale yellow color is a well-known physical property.

White phosphorus is the correct answer. It has been documented as being used by Israeli forces in Gaza, causing severe burns and is controversial under international law. Arsenic is a poison but not primarily an incendiary weapon. Sulphur is used in conventional munitions. Neon is an inert noble gas with no military application as a weapon.