Assertion: The Relative Atomic mass of aluminium is 27
Reason: An atom of aluminium is 27 times heavier than 1/12th of the mass of the C – 12 atom.,

1. A and R are correct, R explains the A.
2. A is correct, R is wrong.
3. A and R are correct, R doesn’t explain A.
4. A is wrong, R is correct.

The correct option is A A and R are correct, R explains the A.
Relative atomic mass of an element is the ratio between the average mass of its isotopes to

$\frac{1}{12}th$ part of the mass of a carbon-12 atom. It is denoted as Ar. It is otherwise called “Standard Atomic Weight”.


If the relative atomic mass of Aluminium is 27 it means that aluminium is 27 times heavier than 1/12th of the mass of the C – 12 atom.,