NEET Chemistry: Atomic Physics questions with solutions

Q1. Which of the following statements is not true about canal rays?

1. They travel in straight line.
2. They are made up of positively charged particles.
3. Their e/m ratio is same for all gases.
4. These rays produce fluorescence on \( Z n S \) screen.

Answer: Their e/m ratio is same for all gases.

Canal rays consist of positive ions, and their charge-to-mass ratio depends on the nature of those ions. Since different gases form different ions, the e/m ratio is not the same for all gases.

Q2. Which of the following is one of the postulates of Rutherford's theory?

1. Electrons continuously lose energy
2. Electrons move in a spiral path around the nucleus
3. Electrons revolve in a specific path around the nucleus
4. Electrons revolve in a stationary orbit

Answer: Electrons revolve in a specific path around the nucleus

Rutherford’s atomic model described a small, dense nucleus with electrons revolving around it in specific paths. The other choices describe later ideas or incorrect behaviors not part of Rutherford’s postulates.