Question

An atom of magnesium has an atomic number of 12 and a mass number of 24.

How many protons plus neutrons are in the nucleus?

Responses

12

12

24

24

36

36

48

48

Answer 1

24

Explanation: atomic number = protons = 12; mass number = protons + neutrons = 24, so there are 24 nucleons in the nucleus.