How many valence electrons does alkali metals gain or lose

Alkali metals have 1 valence electron on their outer shell. They are more stable when they have 8 valence electrons, so they want to lose that valence electron. They do this by bonding with other elements. When they lose their 1 valence electron, they have a full octet and are therefore stable

Explanation:

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.