Question

The mass and energy equivalent to $1amu$ are respectively

• A. $1.67\times {10}^{-27}gm$, $9.30MeV$
• B. $1.67\times {10}^{-27}kg$, $930MeV$
• C. $1.67\times {10}^{-27}kg$,$1MeV$
• D. $1.67\times {10}^{-34}kg$, $1MeV$

Answer 1

The correct option is B $1.67\times {10}^{-27}kg$, $930MeV$

1 amu
It is defined as one twelfth of the mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state.

Mass of 1 mole C atoms $=12gms$
$1amu=$$\frac{12}{12\times 6.023\times {10}^{23}}=1.66\times {10}^{-27}kg$

Energy equivalent, $E=m{c}^2=1.66\times {10}^{-27}kg\times (3\times {10}^8{)}^2$$=930MeV$