Question 39
Radioactivity and Nuclear PhysicsThe mass of a proton is approximately equal to that of
- A.an α-particle
- B.a β-particle
- C.a γ-ray
- D.an electron
- E.a neutron
Show the answer and explanation
Answer: E (a neutron)
Explanation
Protons and neutrons have almost the same mass (about 1 u). An electron or β-particle is about 1840 times lighter and an α-particle about four times heavier.