What is the energy of an electron in stationary state corresponding to n=2 ?

Question

What is the energy of an electron in stationary state corresponding to n=2 ? (A) -3.45 × 10-18 J (B) -0.545 × 10-18 J (C) 0.545 × 10-18 J (D) 3.45 × 10-18 J

Tardigrade Admin · Accepted Answer

Energy of an electron is given by En=(-13.6/n2) eV For n=2 E=(-13.6/2 × 2) eV =(-13.6/4) eV [1 eV =1.602 × 10-19 J ] =-3.4 × 1.602 × 10-19 J =-5.45 × 10-19 J text or =-0.545 × 10-18 J

Q. What is the energy of an electron in stationary state corresponding to $n = 2$ ?

$- 3.45 \times 1 0^{- 18} J$

$- 0.545 \times 1 0^{- 18} J$

$0.545 \times 1 0^{- 18} J$

$3.45 \times 1 0^{- 18} J$

Energy of an electron is given by
$E_{n} = \frac{- 13.6}{n ^{2}} e V$
For $n = 2$
$E = \frac{- 13.6}{2 \times 2} e V = \frac{- 13.6}{4} e V$
$[1 e V = 1.602 \times 1 0^{- 19} J]$
$= - 3.4 \times 1.602 \times 1 0^{- 19} J$
$= - 5.45 \times 1 0^{- 19} J$
$or = - 0.545 \times 1 0^{- 18} J$

Q. What is the energy of an electron in stationary state corresponding to n=2 ?

−3.45×10−18J

−0.545×10−18J

0.545×10−18J

3.45×10−18J