Question

Assertion (A): One atomic mass unit is defined as one-twelfth of the mass of one carbon-12 atom.

Reason (R): Carbon-12 isotope is the most abundunt isotope of carbon and has been chosen as standard.

Options

• Both A and R are true and R is the correct explanation of A.

• Both A and R are true but R is not the correct explanation of A.

• A is true but R is false.

• Both A and R are false.

Answer 1

Both A and R are true but R is not the correct explanation of A.

Explanation:

Atomic mass unit is defined as a mass that is equal to accurately `1/12` the mass of carbon-12 atom.

When scientists compare the relative atomic masses of the elements to the mass of carbon, they find that they are near to a whole number value.