Key words why a rusty nail is chemical

answer

i think the answer is a) as air pressure in an area increases, the density of the gas particles in that area decreases.

hope it

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.