Question

which of the following elements has a max of 3 energy levels?
c
ca
si

Explanation:

Step1: Recall electron - shell rules

Elements in the third period of the periodic table have a maximum of 3 energy levels.

Step2: Identify period of elements

Carbon (C) is in the second period, calcium (Ca) is in the fourth period, and silicon (Si) is in the third period.

Answer:

Si