Question

The mass number of atom is 31. The third shell of this atom contains 5 electrons.
a. Write the electronic configuration of the atom ?
b. What is its atomic number​

Answer 1

Explanation:

a) 2, 8, 5.

b)15.

Hope it is clear.

Answer 2

Answer:

Electronic configuration- 2,8,5

Atomic number- 15

Explanation:

Element is phosphorus