Question

question 6 (1 point)
what is the highest energy level (valence shell) an electron will occupy in ca?
a 4s²
b 4p¹
c 4s¹
d 4p²

Explanation:

Calcium (Ca) has an atomic number of 20. Its electron - configuration is $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}$. The outermost (valence) shell electrons are in the 4s orbital with 2 electrons.

Answer:

A. $4s^{2}$