The energy of an electron in an excited hydrogen atom is -3.4 eV . Its angular momentum is

Question

The energy of an electron in an excited hydrogen atom is -3.4 eV . Its angular momentum is (A)  3.72× 10-34J-s (B) 2.11 × 10-34J-s (C) 1.57 × 10-34J-s (D) 1.11 × 10-34J-s

Tardigrade Admin · Accepted Answer

Energy of electron in nth energy level in hydrogen atom

= - \frac{136}{n ^{2}} e V

Here,

- \frac{13.6}{n ^{2}} = - 3.4 e V

So,

n = 2

Angular momentum from Bohrs principle

= n \frac{h}{2 π}

= \frac{2 \times 6.626 \times 1 0 ^{- 34}}{2 \times 314}

= 2.11 \times 1 0^{- 34} J - s

Q. The energy of an electron in an excited hydrogen atom is $- 3.4 e V$ . Its angular momentum is

$3.72 \times 1 0^{- 34} J - s$

$2.11 \times 1 0^{- 34} J - s$

$1.57 \times 1 0^{- 34} J - s$

$1.11 \times 1 0^{- 34} J - s$

Energy of electron in nth energy level in hydrogen atom
$= - \frac{136}{n ^{2}} e V$
Here, $- \frac{13.6}{n ^{2}} = - 3.4 e V$
So, $n = 2$
Angular momentum from Bohrs principle
$= n \frac{h}{2 π}$
$= \frac{2 \times 6.626 \times 1 0 ^{- 34}}{2 \times 314}$
$= 2.11 \times 1 0^{- 34} J - s$

Q. The energy of an electron in an excited hydrogen atom is −3.4eV . Its angular momentum is

3.72×10−34J−s

2.11×10−34J−s

1.57×10−34J−s

1.11×10−34J−s