Oxygen
Yes, it'll react similiarly to sodium in the air.
Iron can react with water in the presence of air and form rust.
yes
Sodium will normally not react with air. However, it will react with Chlorine. However, that shouldn't be in the air. It will also react with water, but again you need too much water for the air to hold really. That said, going into a steam room with a lump of it would be a bad idea.
When iron reacts with air, they form ferric oxide.
Yes, sodium can react vigorously with water to form sodium hydroxide and hydrogen gas. It can also react with oxygen in the air to form sodium oxide. Additionally, sodium can react with nonmetals, such as chlorine, to form ionic compounds like sodium chloride.
Hydrochloric acid can react with iron in the absence of air to produce iron chloride and hydrogen gas. The reaction between hydrochloric acid and iron is a chemical reaction that does not require oxygen from the air.
Halogens react with air to form metal halides. For example, chlorine will react with iron to form iron(III) chloride. Halogens are highly reactive and will readily form compounds with many elements in the air.
Oxygen (which react with sodium) is not dissolved in kerosene.
Sodium chloride doesn't react with air; being hygroscopic NaCl absorb water from air.
Iron reacts with oxygen in air to for rust.
Sodium is very reactive and easily react with oxygen or water.