In the reaction of lithium, Li, with nitrogen, N₂, three lithium atoms react with one nitrogen atom to give the compound Li₃N. Atoms of one of these elements lose one electron; atoms of the other element gain three electrons.

(a) Which element gains the three electrons? Explain your choice.

(b) Does the element that gained three electrons become a cation or an anion?

(c) Give the full atomic symbol for the ion of part (b), assuming it has seven neutrons in its nucleus.