Target SSC MTS 2025 : If you are preparing for the SSC MTS 2025 exam, Radioactivity is an important topic in General Science. It happens when an unstable atom releases energy or small particles on its own. It was discovered by Henri Becquerel and later studied by Marie Curie. There are three types of radioactive rays: Alpha (α) rays, which are heavy and positively charged particles, Beta (β) rays, which are fast-moving electrons or positrons, and Gamma (γ) rays, which are powerful light rays. This is an important topic for the exam, so understand it well!
Target SSC MTS 2025: Radioactivity Questions
1. What are elements with atomic numbers greater than 82 called?
a) Stable elements
b) Radioactive elements
c) Inert elements
d) Noble gases
2. What is the continuous emission of rays from radioactive elements called?
a) Radiation
b) Radioactivity
c) Ionization
d) Fission
3. Beta particles are also known as:
a) Protons
b) Neutrons
c) Flow of electrons
d) Positrons
4. What is the velocity of a beta particle?
a) Equal to the speed of light
b) Half the speed of light
c) 1/10th the speed of light
d) Twice the speed of light
5. Who discovered radioactivity?
a) Marie Curie
b) Ernest Rutherford
c) Henri Becquerel
d) Niels Bohr
6. What is the unit of radioactivity?
a) Curie
b) Rutherford
c) Becquerel
d) All of the above
7. Who discovered gamma particles?
a) Paul Villard
b) Marie Curie
c) Ernest Rutherford
d) Henri Becquerel
8. What is the charge on a gamma particle?
a) Positive
b) Negative
c) Neutral
d) Double positive
9. Which of the following is a natural radioactive substance?
a) Uranium
b) Thorium
c) Radium
d) All of the above
10. Who discovered Radium and Polonium?
a) Marie Curie and Pierre Curie
b) Henri Becquerel
c) Ernest Rutherford
d) Niels Bohr
11. In which year were Marie Curie and Pierre Curie awarded the Nobel Prize?
a) 1903
b) 1911
c) 1920
d) 1935
12. What instrument is used to measure radioactive radiation?
a) Geiger Muller Counter
b) Spectrometer
c) Cyclotron
d) Scintillation counter
13. What do radioactive substances eventually decay into?
a) Lead
b) Uranium
c) Thorium
d) Polonium
14. Why are radioactive nuclei unstable?
a) Due to a higher number of protons
b) Due to a higher number of neutrons
c) Due to a higher number of electrons
d) Due to a higher number of positrons
15. What is the SI unit of radioactivity?
a) Curie
b) Rutherford
c) Becquerel
d) Roentgen
16. Who discovered alpha particles?
a) Ernest Rutherford
b) Marie Curie
c) Henri Becquerel
d) Niels Bohr
17. What is the charge on an alpha particle?
a) Positive
b) Negative
c) Neutral
d) Double negative
18. What is the mass of an alpha particle?
a) Equal to the mass of hydrogen
b) Twice the mass of hydrogen
c) Four times the mass of hydrogen
d) Half the mass of hydrogen
19. What is the velocity of an alpha particle?
a) Equal to the speed of light
b) 1/10th the speed of light
c) Half the speed of light
d) Twice the speed of light
20. Who discovered beta particles?
a) Ernest Rutherford
b) Marie Curie
c) Henri Becquerel
d) Niels Bohr
21. What is the charge on a beta particle?
a) Positive
b) Negative
c) Neutral
d) Double positive
22. What is the mass of a beta particle?
a) Equal to the mass of hydrogen
b) 1/1840th the mass of hydrogen
c) Twice the mass of hydrogen
d) Half the mass of hydrogen
23. What is the velocity of a gamma particle?
a) Equal to the speed of light
b) 1/10th the speed of light
c) Half the speed of light
d) Twice the speed of light
24. What is the effect of gamma particles on photographic plates?
a) Strong effect
b) Moderate effect
c) Least effect
d) No effect
25. What is the nature of gamma rays?
a) Longitudinal wave
b) Transverse wave
c) Particle nature
d) None of the above
26. What is the order of energy among alpha, beta, and gamma particles?
a) Alpha > Beta > Gamma
b) Gamma > Beta > Alpha
c) Beta > Alpha > Gamma
d) Gamma > Alpha > Beta
27. What is the order of penetrating power among alpha, beta, and gamma particles?
a) Alpha > Beta > Gamma
b) Gamma > Beta > Alpha
c) Beta > Alpha > Gamma
d) Gamma > Alpha > Beta
28. What is the sequence of impact on the photographic plate among alpha, beta, and gamma particles?
a) Alpha > Beta > Gamma
b) Gamma > Beta > Alpha
c) Beta > Alpha > Gamma
d) Gamma > Alpha > Beta
29. Who gave the group displacement rule?
a) Marie Curie
b) Ernest Rutherford
c) Fredrick Soddy and Kasimeirz Fajan
d) Niels Bohr
30. What happens when a radioactive substance emits an alpha particle?
a) Atomic number decreases by 2, atomic mass decreases by 4
b) Atomic number increases by 1, atomic mass remains unchanged
c) Atomic number decreases by 1, atomic mass decreases by 2
d) Atomic number increases by 2, atomic mass increases by 4
Target SSC MTS 2025: Radioactivity Answers
Here are the Answers:
- b) Radioactive elements
- b) Radioactivity
- c) Flow of electrons
- c) 1/10th the speed of light
- c) Henri Becquerel
- d) All of the above
- a) Paul Villard
- c) Neutral
- d) All of the above
- a) Marie Curie and Pierre Curie
- a) 1903
- a) Geiger Muller Counter
- a) Lead
- b) Due to a higher number of neutrons
- c) Becquerel
- a) Ernest Rutherford
- a) Positive
- c) Four times the mass of hydrogen
- b) 1/10th the speed of light
- a) Ernest Rutherford
- b) Negative
- b) 1/1840th the mass of hydrogen
- a) Equal to the speed of light
- c) Least effect
- b) Transverse wave
- b) Gamma > Beta > Alpha
- b) Gamma > Beta > Alpha
- a) Alpha > Beta > Gamma
- c) Fredrick Soddy and Kasimeirz Fajan
- a) Atomic number decreases by 2, atomic mass decreases by 4