Respuesta :

Answer:

26

Explanation:

Given parameters:

Number of neutrons  = 14

Unknown:

Mass number  = ?

Solution:

The mass number of an atom is the sum of protons and neutrons in the atom.

 mass number = number of protons + number of neutrons

Since the atom here is magnesium, number of protons is 12

Mass number = 14 + 12  = 26