Question

question 6 of 30 which best describes an alpha particle that is emitted during nuclear decay? a. a positron b. a hydrogen nucleus c. an electron d. a helium nucleus

Explanation:

To determine the correct description of an alpha particle emitted during nuclear decay, we analyze each option:

• Option A: A positron is a positively charged electron (antiparticle of electron) and is emitted in positron emission, not alpha decay. So A is incorrect.
• Option B: A hydrogen nucleus has 1 proton. An alpha particle has 2 protons and 2 neutrons, so B is incorrect.
• Option C: An electron is emitted in beta - decay (beta - particle), not alpha decay. So C is incorrect.
• Option D: An alpha particle consists of 2 protons and 2 neutrons, which is the same as a helium nucleus (since helium has an atomic number of 2 and a mass number of 4, with 2 protons and 2 neutrons in its nucleus). So D is correct.

Answer:

D. A helium nucleus