Question

According to Bohr's atomic theory, which of the following relations is/are incorrect?

• A. Kinetic energy of electron $\propto \frac{z^2}{n^2}$
• B. The product of velocity of electron and the principal quantum number $\propto z^2$
• C. Frequency of revolution of the electron in an orbit $\propto \frac{z^2}{n^3}$
• D. Coulombic force of attraction on the electron $\propto \frac{z^2}{n^4}$

Answer 1

Answer: (B), (D)

The product of velocity of electron and the principal quantum number $\propto z^2$
Coulombic force of attraction on the electron $\propto \frac{z^2}{n^4}$

(A) According to the Bohr's atomic theory, the kinetic energy of an electron is directly proportional to the square of the atomic number and inversely proportional to the square of the principal quantum number. Thus the statement A is correct.
(B) The product of the velocity of electron and the principal quantum number is proportional to Z. Thus the statement B is incorrect.
(C) Frequency of revolution of the electron in an orbit is directly proportional to the square of the atomic number and inversely proportional to the cube of the principal quantum number. Thus the statement C is correct.
(D) Coulombic force of attraction on the electron is directly proportional to the square of the atomic number and inversely proportional to the fourth power of the principal quantum number. Thus the statement D is correct.