Question

The velocity of an electron in the first Bohr orbit of a hydrogen atom is:

• A. $3.08\times {10}^{6}m/s$
• B. $2.18\times {10}^{6}m/s$
• C. $2.78\times {10}^{6}m/s$
• D. none of these

Answer 1

Answer: (B)

$2.18\times {10}^{6}m/s$

The velocity of the electron is $n^{th}$ Bohr orbit

V = $\frac{V_{0}Z}{n}$ ($V_0=2.18x{10}^6\frac{m}{s}$)

For 1st orbit of hydrogen (Z=1)

V = $\frac{V_0\left(1\right)}{1}$ = $V_0$

Hence, the velocity of an electron in the 1st bohr orbit of a hydrogen is $2.18\times {10}^6\frac{m}{s}$