Question

What is the largest principal quantum number that a calcium electron can have?

• A. $n=4$
• B. $n=3$
• C. $n=2$
• D. $n=1$
• E. $n=0$

Answer 1

Answer: (A)

$n=4$

$1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^2$ this is the electronic configuration of the $Ca$.
4 is the principal quantum number for the last electron that is added to potassium.