Consider the following statements:

Statement I: One atomic mass unit is defined as 1/12 of the mass of one carbon-12 atom.

Statement II: Carbon-12 isotope is the most abundant isotope of carbon and has been chosen as standard.

In the light of the above statements, choose the most appropriate answer from the options given below:

A. Statement I is correct but Statement II is incorrect.
B. Statement I is incorrect but Statement II is correct.
C. Both Statement I and Statement II are correct.
D. Both Statement I and Statement II are incorrect.

Both Statement I and Statement II are correct. Statement I accurately describes the definition of an atomic mass unit, and Statement II correctly states that carbon-12 is the most abundant isotope of carbon and has been used as the atomic mass standard. Therefore, the chosen option is C.
;

Answered by Anonymous | 2025-07-04

Let's examine each statement one by one:
Statement-I : One atomic mass unit is defined as 12 1 ​ of the mass of one carbon-12 atom.
This statement is correct. The atomic mass unit (amu), also known as the unified atomic mass unit (u), is defined exactly as 12 1 ​ of the mass of a carbon-12 atom. Carbon-12 is assigned a mass of exactly 12 atomic mass units, and this definition was adopted in 1961. This makes it a convenient standard for expressing atomic and molecular weights.
Statement-II : Carbon-12 isotope is the most abundant isotope of carbon and has been chosen as a standard.
This statement is also correct. The carbon-12 isotope is indeed the most abundant isotope of carbon, making up about 98.89% of all carbon found in nature. Its stability and abundance make it an ideal standard against which other atomic masses are measured.
Conclusion: Both Statement-I and Statement-II are correct.
Thus, the most appropriate answer is:
(C) Both Statement I and Statement II are correct.

Answered by SophiaElizab | 2025-07-06