The atoms of different elements having same mass number but different atomic number are known as isobars.
The sum of protons and neutrons, in the isobars is always different.

Options

A. If both the assertion and reason are true statement and reason is correct explanation of the assertion .
B. If both the assertion and reason are true statement but reason is not a correct explanation of the assertion .
C. If the assertion is true but the reason is a false statement.
D. If both assertion and reason are false statements.

Answer

C

Explanation

Isobars are the atoms of the different elements having same atomic weight or mass number . It means the sum of protons and neutrons will be same . Atomic number of isobars are different .