Question

The energy of an electron in first Bohr orbit of $H$ - atom is $- 13.6\, eV$. The energy value of electron in the excited state of $Li^{2+}$ is :

• A. -27.2 eV
• B. 30.6 eV
• C. -30.6 eV
• D. 27.2 eV

Answer 1

Answer: (C)

-30.6 eV

Answer 2

Energy of $e^{-}$ in the excited state of $Li^{+2}$
$E=-13.6 \frac{Z^{2}}{n^{2}}$
$=-13.6\times\frac{\left(3\right)^{2}}{\left(2\right)^{2}} e V$
$=-\frac{9}{4} \times13.6 \,eV$
$=-30.6\, e N$