10th class Physics, Chapter 20: Atomic and Nuclear Physics MCQs

1. What did Rutherford's alpha particle scattering experiment reveal about the structure of the atom?

1. (A) Electrons are distributed evenly throughout the atom
2. (B) Protons and electrons are located in the nucleus
3. (C) Atoms are indivisible and indestructible
4. (D) The nucleus is small, dense, and positively charged ✓

2. The atomic number of an element represents:

1. (A) number of neutrons in the nucleus
2. (B) number of protons in the nucleus ✓
3. (C) total number of protons and neutrons
4. (D) number of electrons and neutrons

3. Which type of radiation is positively charged and consists of two protons and two neutrons?

1. (A) Alpha (α) ✓
2. (B) Beta (β)
3. (C) Gamma (γ)
4. (D) Neutron emission

4. The process by which an unstable nucleus emits radiation and transforms into a more stable nucleus is called:

1. (A) nuclear fusion
2. (B) nuclear fission
3. (C) radioactive decay ✓
4. (D) isotopic exchange

5. Nuclear fission involves:

1. (A) combining light nuclei to form heavier ones
2. (B) splitting heavy atomic nuclei into smaller ones ✓
3. (C) absorbing gamma radiation to increase stability
4. (D) none of the above

6. What does Einstein's equation E = mc² explain?

1. (A) The energy released in chemical reactions
2. (B) The equivalence of mass and energy ✓
3. (C) The rate of radioactive decay
4. (D) The conversion of mass into momentum

7. Which of the following is a practical application of nuclear radiations?

1. (A) Cooking food in microwave ovens
2. (B) Medical imaging and cancer treatments ✓
3. (C) Solar energy generation
4. (D) Airplane navigation systems

8. What are the potential effects of ionizing nuclear radiation on biological tissues?

1. (A) Increased cellular regeneration
2. (B) DNA damage and cancer ✓
3. (C) Enhanced immune system response
4. (D) Improved metabolic activity

9. In Rutherford's experiment, most of the alpha particles passed through the gold foil undeflected, showing that:

1. (A) an atom is mostly empty space ✓
2. (B) an atom is solid
3. (C) the nucleus is large
4. (D) electrons are heavy

10. The few alpha particles that bounced back in Rutherford's experiment showed that:

1. (A) the nucleus is small and dense and positively charged ✓
2. (B) the electrons are heavy
3. (C) the atom is a solid sphere
4. (D) neutrons repel alpha particles

11. The alpha particle scattering experiment was performed with a thin foil of:

1. (A) aluminium
2. (B) gold ✓
3. (C) copper
4. (D) iron

12. The nucleus is about ____ times smaller than the entire atom.

1. (A) 100
2. (B) 2
3. (C) 10 000 ✓
4. (D) 10

13. The nucleus of an atom contains:

1. (A) neutrons and electrons
2. (B) only electrons
3. (C) protons and neutrons ✓
4. (D) protons and electrons

14. The number of neutrons in a nucleus is given by:

1. (A) N = Z − A
2. (B) N = A × Z
3. (C) N = A − Z ✓
4. (D) N = A + Z

15. The mass number of an atom is the total number of:

1. (A) protons and neutrons ✓
2. (B) protons and electrons
3. (C) neutrons and electrons
4. (D) electrons only

16. Isotopes of an element have the same number of:

1. (A) neutrons
2. (B) nucleons
3. (C) mass number
4. (D) protons ✓

17. Deuterium ²₁H contains:

1. (A) 1 proton and 0 neutrons
2. (B) 1 proton and 2 neutrons
3. (C) 2 protons and 1 neutron
4. (D) 1 proton and 1 neutron ✓

18. The number of neutrons in carbon-14 (¹⁴₆C) is:

1. (A) 6
2. (B) 7
3. (C) 14
4. (D) 8 ✓

19. Radioactivity was discovered by:

1. (A) Albert Einstein
2. (B) J. J. Thomson
3. (C) Henri Becquerel ✓
4. (D) Ernest Rutherford

20. Marie Curie discovered the elements:

1. (A) polonium and radium ✓
2. (B) uranium and thorium
3. (C) cobalt and iodine
4. (D) carbon and nitrogen