(Sodium) Na atom is more likely to give electron in Gaseous state because its first Ionization energy is less than (Lithium) Li .
Explanation:
This is because the size of Na(g) atom is bigger than the (Lithium) Li (g) atom due to the presence of one more Shell.
Thus the outermost e^-of Na(g)atom is far away from nucleus than the outermost e^-in Li(g) atom, so it is more easy for the e^- to be released from Na(g)atom.