Question

The ratio of mass of electrons in ${}_{92}{U^{235}}^{}$ with that of its nucleus is
(mass of electron $=0.00055a.m.u.$)

• A. $2.15\times {10}^4$
• B. $5.21\times {10}^4$
• C. $2.15\times {10}^{-4}$
• D. $5.21\times {10}^{-4}$

Answer 1

The correct option is C $2.15\times {10}^{-4}$

mass of a electron $=0.00055$ a.m.u

mass of nucleus (here) $=235$ a.m.u

no. of electrons =no. of protons $=92$ a.m.u

$\begin{array}{c}\text{ratio}=\frac{92\times 0.00055}{235}\end{array}$

$2.15\times {10}^{-4}$