Essentially Nitrogen - Life with Element 7! Quiz

Answer: Nitre forming

Credit for discovering nitrogen is commonly given to Scottish scientist Daniel Rutherford in 1772. British scientist, Henry Cavendish and Swedish (Pomeranian) scientist Carl Scheele, also found nitrogen around the same time. The name nitrogen is derived from 'nitre forming' where nitre is still the common name for potassium nitrate (which is also, and somewhat confusingly called saltpetre) and used in gunpowder and fertilizer.

The name 'nitrogen' was proposed nearly 20 years after the discovery of the element after it was determined that it was found in nitric acid and nitrate salts.

Answer: Nitrogen gas is a major component of the air we breathe

Nitrogen gas makes up 78% of the air we breathe. It is by far the largest component of the atmosphere. Oxygen is second at 21% with all other gases making up the last 1%. The composition of the atmosphere was largely determined by the late 18th century when it was believed to contain four gases - nitrogen, oxygen, carbon dioxide and water vapor.

The inert gas argon, which is the third largest component at 0.9%, was discovered much later in 1894. Although the actual amounts (concentrations) of the gases change significantly with atmospheric pressure (e.g. much lower concentrations of all gases at high altitudes), the relative proportions of the gases remain almost constant. Carbon dioxide concentrations are changing but this gas makes up only 0.04% of the atmosphere.

Answer: 77K = -196C = -321F

Liquid nitrogen boils at 77 degrees Kelvin (= -196 degrees Celsius and -321 degrees Fahrenheit). It is a colorless liquid. On larger scales it is stored in insulated containers and flasks/dewars. Your local doctor or dermatologist often uses a spray bottle with a very fine nozzle to direct the liquid nitrogen onto the wart.

The extremely cold temperature causes a cryogenic burn that kills the wart cells. If handled carefully, liquid nitrogen can be a fun addition to science demonstrations - for example, bananas can be frozen and then dropped.

They then shatter into pieces! Careful handling is essential though as cryogenic (extreme cold) burns, like the more common 'hot burns', can be very serious, perhaps even fatal, if too much skin is affected.

The first temperature unit used in this question is 'Kelvin'. It is frequently used by scientists and engineers and is based on the concept of absolute zero - that temperature when all molecular motion stops - this is 0 degrees Kelvin.

Answer: The N to N triple bond

The nitrogen to nitrogen triple bond means that it requires a large amount of energy to separate the two nitrogen atoms in (di)nitrogen gas. The more energy required to break chemical bonds, the less likely it is that the molecule will react - hence it is more inert (non-reactive).

The triple bond has three pairs of electrons drawing the two N atoms together. Apart from dinitrogen, triple bonds are very uncommon in the world around us. The only other common examples are cyanide and the gas acetylene often used in welding, which has a carbon to carbon triple bond.

Answer: Yes, it dissolves readily in water

Like all gases, (di)nitrogen gas will readily dissolve in water. The exact amount dissolved (the concentration) depends on the water temperature and, to a lesser extent, the salinity of the water. Unlike most solids (e.g. common salt, sugar), the warmer the temperature of the water, the less gas will dissolve. You can check this out for yourself! Bring some water up to the boil. Before it boils, you will see lots of small bubbles.

This is the gas (including nitrogen) that is no longer soluble in the hot water.

Answer: 1s2, 2s2, 2p3

Electronic structure is arguably the most important explanatory concept learned by students of chemistry. Understanding of electronic structure was greatly advanced by Danish physicist, Niels Bohr (1885-1962), who proposed that electrons move around the nucleus of an atom in 'orbitals' (labelled, s, p, d and f) and that these orbitals were then arranged in order of increasing energy. Electrons would fill the lowest energy orbitals first.

The first orbital, the 1s, can contain 2 electrons. The next is 2s, which can also contain 2 electrons.

The third lowest energy orbital is the 2p shell which can hold up to 6 electrons (split into 3 sub-levels of 2 electrons each). Hence with the 7 electrons for nitrogen, the configuration is 1s2 (the 1s orbital with 2 electrons), 2s2 (the second s orbital with 2 electrons) and a half-filled 2p orbital - 2p3.

Answer: Proteins

Nitrogen is an essential constituent of all proteins. Proteins are made up of large numbers of amino acids. In turn, all amino acids contain both a carboxylic acid group (-COOH) and an amine group (-NH2), each bound to a variety of other atoms along a carbon 'backbone'.

These other atoms distinguish the identity of the 20 amino acids found in the human genome. It is the order and identity of the amino acids making up a protein that determine the structure and function of that protein.

Answer: Laughing Gas

Laughing gas has been used as an anaesthetic in medicine (including dentistry) from the middle of the 19th century. Most commonly used in combination with oxygen, nitrous oxide can also have euphoric effects upon inhalation, hence its common name. From personal experience it also makes you talk in a squeaky voice! At higher concentrations, it is a powerful oxidant and has been used in rocket fuels and internal combustion engines ('nitro' fuel).

Answer: Cyanide

Strictly speaking, 'cyanide' is not a compound but rather a negatively charged ion (anion). Its chemical formula is CN-, so one carbon atom is bound to one nitrogen atom (with a triple bond). Hence this anion needs an accompanying cation to balance the charge.

This cation can be a common metal such as sodium (Na+) or Potassium (K+) or the hydrogen cation (H+). In the latter case, the compound is HCN, known as hydrogen cyanide and also prussic acid. The cyanide acts by suppressing enzymes responsible for respiration (breathing). Accidental, usually fatal, poisoning of cattle occurs through ingestion of cyanide-rich sorghum plants.

Other plants containing cyanide at various stages of their life cycle include cassava, bitter almonds, peaches, apricots and apple seeds.

There is nowhere near enough cyanide in apple seeds to cause any danger from accidental ingestion!

Answer: Ammonia

During the first decade of the 20th century, Fritz Haber and Carl Bosch developed a process to convert inert nitrogen gas (an effectively inexhaustible supply of nitrogen) into ammonia. This process has made a massive contribution to help feed the world's increasing population. (Di)nitrogen gas is reacted with hydrogen gas in a 1:3 ratio to generate ammonia according to the reaction N2 + 3 H2 -> 2 NH3 (where NH3 is ammonia).

This process operates under high pressure and a temperature of 400-500C while passing the gas over a metal-based catalyst. Research is always continuing on improving the efficiency of the catalyst as the process is extremely energy intensive.

The source of the hydrogen is usually from treatment of methane (CH4) from natural gas deposits.