Correct Answer - Option 2 : 2.1 × 10
-34 J s
The correct answer is option 2) i.e. 2.1 × 10-34 J s
CONCEPT:
According to Bohr's Theory,
- The energy of an electron (eV) in the nth orbit of H-atom is given by:
E = \(\frac{-13.6}{n^2}\)
- The angular momentum of an electron in nth orbit is given by:
L = \(\frac{nh}{2\pi}\)
Where h is the Planck's constant (6.627 × 10-34 m2 kg/s)
CALCULATION:
Given that:
Energy of the electron, E = - 3.4 eV
E = \(\frac{-13.6}{n^2}\)
-3.4 = \(\frac{-13.6}{n^2}\) ⇒ n = 2
Angular momentum, L = \(\frac{nh}{2\pi} = \frac{2\times 6.627 \times 10^{-34}}{2\pi} = \) 2.1 × 10-34 J s
- joules-second (J s) is the SI unit of angular momentum apart from kg m2 s-1.