Question
What is the velocity of electron present in first Bohr orbit of hydrogen atom ?
A.
$$2.18 \times {10^5}\,m/s$$
B.
$$2.18 \times {10^6}\,m/s$$
C.
$$2.18 \times {10^{ - 18}}\,m/s$$
D.
$$2.18 \times {10^{ - 9}}\,m/s$$
Answer :
$$2.18 \times {10^6}\,m/s$$
Solution :
$$\eqalign{
& {\text{From Bohr's theory}}, \cr
& \nu = 2.18 \times {10^6} \times \frac{Z}{n}m/s \cr
& \,\,\,\,\, = 2.18 \times {10^6} \times \frac{1}{1} \cr
& \,\,\,\,\, = 2.18 \times {10^6}\,m/s \cr} $$