Nitrogen (Azote)
Atomic Number: 7
Symbol: N (Az, French)
Atomic Weight: 14.00674
Discovery: Daniel Rutherford 1772 (Scotland): Rutherford removed oxygen and carbon dioxide from air and showed that the residual gas would not support combustion or living organisms.
Electron Configuration: [He]2s22p3
Word Origin: Latin: nitrum, Greek: nitron and genes; native soda, forming. Nitrogen was sometimes referred to as 'burnt' or 'dephlogisticated' air. The French chemist Antoine Laurent Lavoisier named nitrogen azote, meaning without life.
Properties: Nitrogen gas is colorless, odorless, and relatively inert. Liquid nitrogen is also colorless and odorless, and is similar in appearance to water. There are two allotropic forms of solid nitrogen, a and b, with a transition between the two forms at -237° C. Nitrogen's melting point is -209.86° C, boiling point is -195.8° C, density is 1.2506 g/l, specific gravity is 0.0808 (-195.8° C) for the liquid and 1.026 (-252° C) for the solid. Nitrogen has a valence of 3 or 5.
Uses: Nitrogen compounds are found in foods, fertilizers, poisons, and explosives. Nitrogen gas is used as a blanketing medium during the production of electronic components. Nitrogen is also used in annealing stainless steels and other steel products. Liquid nitrogen is used as a refrigerant. Although nitrogen gas is fairly inert, soil bacteria can 'fix' nitrogen into a usable form, which plants and animals can then utilize. Nitrogen is a component of all proteins. Nitrogen is responsible for the orange-red, blue-green, blue-violet, and deep violet colors of the aurora.
Sources: Nitrogen gas (N2) makes up 78.1% of the volume of the Earth’s air. Nitrogen gas is obtained by liquefaction and fractional distillation from the atmosphere. Nitrogen gas also can be prepared by heating a water solution of ammonium nitrite (NH4NO3). Nitrogen is found in all living organisms. Ammonia (NH3), an important commercial nitrogen compound, is often the starting compound for many other nitrogen compounds. Ammonia may be produced using the Haber process.
Element Classification: Non-Metal
Density (g/cc): 0.808 (@ -195.8°C)
Appearance: colorless, odorless, tasteless, and mainly inert gas
Atomic Radius (pm): 92
Atomic Volume (cc/mol): 17.3
Covalent Radius (pm): 75
Ionic Radius: 13 (+5e) 171 (-3e)
Specific Heat (@20°C J/g mol): 1.042 (N-N)
Pauling Negativity Number: 3.04
First Ionizing Energy (kJ/mol): 1401.5
Oxidation States: 5, 4, 3, 2, -3
Lattice Structure: Hexagonal
Lattice Constant (Å): 4.039
Lattice C/A Ratio: 1.651
Magnetic Ordering: diamagnetic
Thermal Conductivity (300 K): 25.83 m W·m−1·K−1
Speed of Sound (gas, 27 °C): 353 m/s
CAS Registry Number: 7727-37-9
References: Los Alamos National Laboratory (2001), Crescent Chemical Company (2001), Lange's Handbook of Chemistry (1952)
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