Assertion (A) : One atomic mass unit is defined as one twelfth of the mass of one carbon-12 atom. Reason (R) : Carbon - 12isotope is the most abundant isotope of carbon and has been chosen as standard.

Assertion (A) : One atomic mass unit is defined as one twelfth of the

1.	Assertion (A) : One atomic mass unit is defined as one twelfth of the mass of one carbon-12 atom. Reason (R) : Carbon - 12isotope is the most abundant isotope of carbon and has been chosen as standard.
Answer» Both A and R are TRUE and R is the correct EXPLANATION of A. Both A and R true but R is not the correct explanation of A. A is true but R is false. Both A and R are false. Solution :ATOMIC masses of the elements obtained by comparing with the mass of carbon comes out to be close to whole number value.