In each of the following question, an Assertion (A) is following by a corresponding Reason (R ). Use the following keys to choose the appropriate answer.
Assertion : Average atomic mass of an element depends upon the atomic masses of different isotopes and their fractional abundances.
Reason : Average atomic mass is obtained by multiplying the atomic mass of the heavier isotope with its fractional abundances.

Options

A. If both (A) and ( R ) are correct and ( R ) is the correct explanation of (A).
B. If both (A) and (R ) are correct, but ( R ) is not the correct explanation of (A).
C. If (A) is correct, but ( R) is incorrect.
D. If both (A) and (R ) are incorrect.

Answer

C

Explanation

Average atomic mass is obtained by multiplying atomic masses of the isotopes with their corresponding fraction abundances and then adding.