Nitrogen molecule is diatomic, whereas other elements form tetraatomic molecules.
The answer is D, all of them have very different masses
Multiply the mass by the abundance and add each. Make sure to convert the percentage into a decimal. (49.946 * .043) + (51.941 * .838) + (52.941 * .095) + (53.939 * .024) = 51.99 round up using sig figs and the answer is c. 52.00 amu