Nitrogen
Nitrogen (7N) in the elemental form was considered to be inert and was even named ozote which refers to the fact that it is not reactive. Of course nitrogen does form compounds, but the gaseous form consists of diamers (2 nitrogens bonded together). The diamer is very stable. Nitrogen is a major element in organic compounds, especially proteins. Some nitrogen compounds are highly reactive. Trinitrotoluene is TNT, or dynamite. Ammonium Nitrate is a fertilizer, but was used as the major explosive ingredient in the Oklahoma City bombing. Anfo, or Ammonium Nitrate and fuel oil mixture, is the primary explosive used in the mining industry because it is inexpensive, easy to manufacture and can be easily manufactured near the mine site thus reducing the risks and expenses related to the transportation of explosives. Nitrates, Nitrites and Azides (all nitrogen compounds are either oxidizers or reactives and will react violently under the right conditions. Nitrogen has many industrial uses in the gaseous forms, but probably the most interesting is liquid nitrogen, which is extremely cold. Items that must be frozen to extremely low temperatures for preservation are frequently stored in liquid nitrogen. Fertility clinics store sperm, eggs and embryos used to help infertile couples become pregnant in ampoules in liquid nitrogen.Since nitrogen gas is very stable, at standard temperature and pressure, it is used as the air in inert welding atmospheres. Documents, foods and chemicals are sometimes stored in nitrogen to keep them from oxidizing or reacting with air or water. Nitrogen can be made by liquification and then fractional distillation of the air. It is very easily done commercially. It can also be made by heating NaN3 to 300°C.
Phosphorus
Phosphorus (15P) is commonly misspelled "phosphorous". It is an essential component of living systems and is found in nervous tissue, bones and cell protoplasm. Phosphorus exists in several allotropic forms including white (or yellow), red, and black (or violet). White phosphorus has two modifications. Ordinary phosphorus is a waxy white solid. When pure, it is colourless and transparent. It is insoluble in water, but soluble in carbon disulphide. It catches fire spontaneously in air, burning to P4O10, often misnamed as phosphorus pentoxide. When exposed to sunlight, or when heated in its own vapour to 250°C, it is converted to the red variety. This form does not ignite spontaneously and it is a little less dangerous than white phosphorus. The red modification is fairly stable and sublimes with a vapour pressure of 1 atmosphere at 417°C.
Arsenic
Arsenic (33As) occurs in two solid modifications: yellow, and grey or metallic, with specific gravities of 1.97, and 5.73, respectively. The element is a steel grey, very brittle, crystalline, semimetallic (metalloid) solid. It tarnishes in air, and when heated rapidly oxidises to arsenous oxide which has a garlic odour. Arsenic and its compounds are poisonous as any reader of "who-done-it" books knows. Upon heating arsenic and some minerals containing arsenic, it sublimes (transfers from the solid to the gaseous state, without passing through the liquid state).
Antimony
Metallic antimony (51Sb) is an extremely brittle metal of a flaky, crystalline texture. It is bluish white and has a metallic lustre. It is not acted on by air at room temperature, but burns brilliantly when heated with the formation of white fumes. It is a poor conductor of heat and electricity. Antimony and its compounds are toxic. It is found mostly with other minerals and in stibnite.
Bismuth
Bismuth (83Bi) is a white, crystalline, brittle metal with a pinkish tinge. Bismuth is the most diamagnetic of all metals, and the thermal conductivity is lower than any metal, except mercury. It has a high electrical resistance, and has the highest Hall effect of any metal (that is, the greatest increase in electrical resistance when placed in a magnetic field).
