Question

what element has the following electron configuration? 1s²2s²2p⁶3s¹
o potassium
o sodium
o lithium
o magnesium

Explanation:

The sum of electrons in the given electron - configuration $1s^{2}2s^{2}2p^{6}3s^{1}$ is $2 + 2+6 + 1=11$. The atomic number of an element is equal to the number of electrons in a neutral atom. Sodium has an atomic number of 11.

Answer:

sodium