How many electrons does boron lose when forming a ion?

A. 1

B. 2

C. 3

D. 4

(NOT D)

(Answer) (C) 3

Boron is a non-metal with atomic number 5. The electronic configuration of boron atom is [He]2s^22p^1.

Boron atom has the tendency to obtain stable electronic configuration like its nearest noble gas helium by losing electrons. Boron atom usually loses 3 electrons from its outermost electronic shell to form a cation with + 3 charge.

Therefore, boron atom loses 3 electrons while forming an ion.