Question

If the speed of electron in the Bohr's first orbit of hydrogen atom is x, the speed of the electron in the third Bohr's orbit is

• A. x/9
• B. x/3
• C. 3x
• D. 9x

Answer 1

Answer: (B)

x/3

Answer 2

According to Bohr's model for hydrogen and hydrogen like atoms the velocity of an electron in an atom is quantised and is given by $v \propto \frac{2\pi Ze^{2}}{nh}$ so $v \propto \frac{1}{n}$ in this cass $n = 3$