Question
The energy of $${e^ - }$$ in first orbit of $$H{e^ + }$$ is $$ - 871.6 \times {10^{ - 20}}J.$$ The energy of $${e^ - }$$ in first orbit of $$H$$ is :
A.
$$ - 871.6 \times {10^{ - 20}}$$
B.
$$ - 435.8 \times {10^{ - 20}}J$$
C.
$$ - 217.9 \times {10^{ - 20}}J$$
D.
$$ - 108.9 \times {10^{ - 20}}J$$
Answer :
$$ - 217.9 \times {10^{ - 20}}J$$
Solution :
$$\eqalign{
& {E_{{1_{H{e^ + }}}}} = {E_{{1_H}}} \times {Z^2} \cr
& \therefore \,\, - 871.6 \times {10^{ - 20}} = {E_{{1_H}}} \times 4 \cr
& \therefore \,\,{E_{{1_H}}} = - 217.9 \times {10^{ - 20}}J \cr} $$