Chemistry · Some Basic Concepts of Chemistry

Given below are two statements: Statement I: One atomic mass unit (amu or u) is defined as a mass exactly equal to one-twelfth the mass of one carbon-12 atom. Statement II: Average atomic mass is calculated by taking the arithmetic mean of atomic masses of all naturally occurring isotopes. In the light of the above statements, choose the most appropriate answer from the options given below:

1. Statement I is correct but Statement II is incorrect.
2. Both Statement I and Statement II are correct.
3. Both Statement I and Statement II are incorrect.
4. Statement I is incorrect but Statement II is correct.