Question

One atomic mass unit is equal to?

(Given, mass of one carbon-12 atom $=1.992\times {10}^{-23}$)

• A. $1.66\times {10}^{-27}g$
• B. $1.66\times {10}^{-24}g$
• C. $1.66\times {10}^{-23}g$
• D. $1.66\times {10}^{-25}g$

Answer 1

Answer: (B)

$1.66\times {10}^{-24}g$

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

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

1 amu $=$ 1/12 mass of carbon-12 atom $=\frac{1}{12}\times 1.992\times {10}^{-23}$ $=1.66\times {10}^{-24}g$