### element | nitrogen:

Liquid nitrogen
* boils at room termperature.
* can be hazardous
  - very dangerous if improperly handled
* can cause severe frostbite
  - terrible burns
  - freeze things
  - increase production rates of moulded products
* cold, liquefied gas that is sprayed on the skin with a spray gun.
* cryogenic fluid that can cause rapid freezing on contact with living tissue
  - liquid
* dangerous material.
* destroys the warts on the skin's surface, but the warts can recur.
* flows by gravity into the laser dewar.
* is abundant and cheaply available
  - applied to external lesions with a Q-tip and feels extremely cold
* is applied to the clinically apparent tumor
  - lesion to destroy malignant tissue by ultra-cold freezing
  - cheaper than beer
  - colder than that
  - colourless while liquid oxygen is blue in colour
  - generally less costly and more readily available than liquid argon
  - just about as dangerous as boiling water, and for all the same reasons
  - much less expensive and easier to handle than liquid helium
  - nitrogen in a liquid state at an extremely low temperature
  - nontoxic but can asphyxiate and cause freeze burns
  - pushed into afflicted structures, freezing walls and termites in their tracks
  - safer and is preferred to liquid oxygen as a cryogenic liquid coolant
  - the largest processing cost in cryogenically cooling gears
* is used as a coolant
  - refrigerant
  - by some medical doctors to destroy minor skin lesions such as warts
  - for cooling
  - in our CCD cameras
* is used to cool certain instruments
  - do experiments at low temperatures
  - explain the effects of cold temperatures on objects
  - freeze the blood
  - keep items frozen at very low temperatures
  - very cold
* lowers the interior temperature, freezing the flashing to make it brittle.
* poses no environmental hazards.
* stock item and can be delivered daily.

Nitrate nitrogen
* is converted to nitrogen gases that are lost to the atmosphere
  - subject to rapid loss from soil, either from leaching or from loss as a gas
* moves with the irrigation water.
* stops ethylene production in soil by poising the redox potential.

### element | nitrogen:

Organic nitrogen
* common component in plant residues and organic matter.
* exists in many different forms.
* includes nitrogen in organic molecules such as amino acids.
* is calculated by taking the difference between total nitrogen and ammonia
  - converted to ammonia in the first step of the nitrogen cycle
  - determined by the difference between total nitrogen and ammonia nitrogen
  - found in proteins, and is continually recycled by plants and animals
  - mineralized into ammonia
* is released as ammonia nitrogen when bacteria decompose organic matter
  - to the soil solution slowly over time

Oxide of nitrogen
* All oxides of nitrogen are polar covalent compounds.
* Oxides of nitrogen are a key component of smog, which causes and aggravates breathing problems
  - important in nitrosamine formation
  - major sources of atmophereic pollution
  - one of the main contributors to ozone
* Oxides of nitrogen can also have adverse effects on plants, reducing growth
  - be irritants and sensitizers
  - contribute the formation of ground-level ozone and photochemical smog

Urea nitrogen
* Can be a signal that hypertension is caused by kidney failure.
* is protein waste, which hurts the dairy farm's profitability.
* waste product resulting from the breakdown of protein in the body.
* water-soluble source of nitrogen.