Question

From Bohr's model, radius of the orbit and energy of the hydrogen atom are calculated as:

• A. the radius of the $1^{st}$ orbit is $0.529A^o$
• B. the energy of the $1^{st}$ orbit is $-13.6eV$
• C. the energy of the $1^{st}$ orbit is $-21.72\times {10}^{-19}J$
  
• D. the radius of the $1^{st}$ orbit is $1.06A^o$

Answer 1

Answer: (A), (B), (C)

The correct options are
A the radius of the $1^{st}$ orbit is $0.529A^o$
B the energy of the $1^{st}$ orbit is $-21.72\times {10}^{-19}J$
C the energy of the $1^{st}$ orbit is $-13.6eV$

For hydrogen 1st orbit, Z = 1 and n = 1.
$Radiusof{1}^{st}orbitofhydrogenatom=0.529\times \frac{n^2}{Z}=0.529{}^{o}A$
$Energyof{1}^{st}orbitofhydrogenatom=-13.6\frac{Z^2}{n^2}=-13.6eV$
$1eV=1.602\times {10}^{-19}J$
$-13.6\times 1.602\times {10}^{-19}=-21.72\times {10}^{-19}J$.