Question

electron configuration & orbital practice
the following electron configuration has

of electrons and belongs to the element

1s²2s²2p⁶3s²3p⁶4s²
9, fluorine
2, fluorine
20, calcium
4, be

Explanation:

Step1: Calculate number of electrons

Sum the exponents: $2 + 2+6 + 2+6 + 2=20$

Step2: Identify element

An element with 20 electrons has an atomic number of 20, which is Calcium.

Answer:

C. 20, Calcium