Question #85204

1 Answer
Dec 15, 2017

Sodium (Na) and Magnesium (Mg)

Explanation:

The number of neutrons in an element can be found by subtracting the atomic number (number of protons) by the mass number (number of nucleons).

Sodium's atomic number is 11 and its mass number is 23.
#23-11=12# neutrons

Checking magnesium: Atomic number = 12
Mass number is 24
#24-12=12# neutrons.

Therefore, the elements with 12 neutrons are sodium and magnesium.