Question

Which of the plots shown in the figure represents speed (v) of the electron in a hydrogen atom as a function of the principal quantum number (n)?

• A. B
• B. D
• C. C
• D. A

Answer 1

Answer: (A)

B

Answer 2

Velocity of electron in $n^{th}$ orbit of hydrogen atom is given by : $V_{n} = \frac{2\pi KZe^{2}}{nh}$ Substituting the values we get. $V_{n} = \frac{2.2 \times10^{6}}{n}$ m/s or $V_{n}\propto \frac{1}{n}$ As principal quantum number increases, velocity decreases.