Answer: One (1) electron
Explanation:
Lithium is a group 1 element with an atomic number of 3. Thus, it has just 3 electrons and its electronic configuration is 1s2, 2s1
To become lithium ion salts, it gives off its lone electron thereby becoming Li+ with configuration of 1s2 with just 2 electrons left.
So, Li atom loses only ONE ELECTRON to become an ion