Answer : The correct option is, (B) 30
Explanation :
Atomic number : It is defined as the number of protons or number of electrons.
Atomic number = number of protons = number of electrons
Atomic mass : It is defined as the sum of number of protons and number of neutrons.
Atomic mass = Number of protons + Number of neutrons
or,
Atomic mass = Atomic number + Number of neutrons
As we are given that,
The element is. Fe
Atomic number = 26
Mass number or atomic mass = 56
Atomic mass = Atomic number + Number of neutrons
Number of neutrons = Atomic mass - Atomic number
Number of neutrons = 56 - 26
Number of neutrons = 30
Therefore, the number of neutrons are, 30