Respuesta :

Atomic number is protons + electrons
Mass number is protons + neutrons
So to calculate the number of neutrons, you do
atomic number - atomic mass
31 - 84 = - 53

Answer:

Atomic number is protons + electrons

Mass number is protons + neutrons

So to calculate the number of neutrons, you do

atomic number - atomic mass

31 - 84 = - 53

Explanation: