Question

An atom has a mass number $A$ and atomic number $Z:$

How many neutrons are present in its nucleus?

Answer 1

Mass number: The total number of protons and neutrons is called the mass number.

• It is represented by A.
• Mass number = the total number of a proton + the total number of neutrons.
• Number of neutron = Mass number – Atomic number OR
• n = A – Z

Atomic number: The total number of proton or electrons in an atom is called atomic the number

• It is represented by Z.
• Atomic number = total number of electrons or a total number of protons.

Neutrons: It is neutral particles of the atom.

• It is represented by n.
• Number of neutron = Mass number – Atomic number OR
• n = A – Z