Question

One atomic mass unit (amu) is equal to

(A) \(1.66\times 10^{-4} g\)

(B) 12 g

(C) \(\frac 1{12} g\)

(D) \(1.67\times 10^{-24} g\)

Answer 1

Correct option is (A) \( 1.67\times 10^{-24} g\)

One atomic mass unit (amu or u) is equal to \(\frac 1 {12}\)th of the mass of an atom of carbon-12.

Mass of an atom of carbon-12 = \(1.992 \times 10^{-23}g\)

1 amu = \(\frac 1 {12}\) mass of carbon-12 atom

\(= \frac1{12} \times 1.992 \times 10^{-23} g\)

\(= 1.67\times 10^{-24} g\)