Question

$1u$ (amu) is equal to

• A. $1.492\times 10^{-10}J$
• B. $1.492\times 10^{-7}J$
• C. $1.492\times 10^{-13}J$
• D. $6.023\times 10^{23}J$

Answer 1

Answer: (A)

$1u=1.66\times 10^{-24}g$

= $1.66\times 10^{-27}kg$

= $1.66\times 10^{-27}\times (3\times 10^8{)}^{2}kg{m}^2{s}^{-2}$

( $\because E=m{c}^2$ )

= 1.494 $\times 10^{-10}J$