Question

The atomic number and mass number for a specimen are ZandA respectively. The number of neutrons in the atom will be

Answer 1

We know that atomic no (Z) = no of electrons/protons
and, mass number (A) = no of neutron + no of electrons

so, no of neutrons = A - Z

Answer 2

Heya!

Atomic number= Z

Mass number = A

Then,

Since, Atomic number (Z) = no. of protons

And,

Mass number = no of protons + no. of neutrons

=) A = Z + no of neutrons

=) No. of neutrons = A - Z

Hence, Number of neutrons = Mass number - Atomic number

Hope it helps u.