They don’t combine with oxygen even at reasonably higher temperatures. Nitrogen is an unreactive gas, and it reluctantly combines with oxygen to form nitric oxide (NO) only at a temperature higher than 1200 degree celsius. As the components or air are non-flammable, air cannot catch fire.

They are isotopes and differ in the number of neutrons even though they have the same number of protons and are the same element. Would a small atom (less than 40 protons) be found in nature if it has the same number of protons & neutrons (1:1 ratio)? Explain. Yes, it would fall within the band of stability.

Safety tips Never smoke or let anyone else smoke while you are using oxygen. Put up “no smoking”signs, and be aware of people smoking near you when you are outside your home. Keep oxygen at least 6 ft (2 m) away from flames or heat sources such as gas stoves, barbecue grills, space heaters, candles, and fireplaces.

At 118 degrees, human skin can sustain first-degree burns; a second-degree burn injury can occur at a temperature of 131 degrees. Human skin is destroyed when temperatures reach 162 degrees.

After the gas warms to the ambient temperature it becomes slightly lighter than air and will rise. So obviously in a small controlled environment liquid nitrogen which has boiled and produced gaseous nitrogen can under some circumstances put out a fire.

The extinguishing effect of inert gases such as argon, nitrogen and carbon dioxide (in principle, this is not an inert gas and is therefore unsuitable for class D fires) is achieved through the displacement of atmospheric oxygen.

Nitrogen is used as a propellant in certain kinds of fire extinguishers, but it isn’t typically used as a fire-fighting gas in itself. It’s dense enough to fall onto a fire, and it will displace oxygen.

Nitrogen gas is only slightly lighter than air and readily mixes with air at room temperature. Cold vapors are more dense and will settle. Liquid nitrogen, a cryogenic liquid, has a very low boil- ing point of –320°F.