Which of the following statements is true for beta radiation?

• A. It results in the emission of an alpha particle (He^{2+}) from the nucleus.
• B. It causes the atomic number to decrease by two.
• C. It does not change the atomic number of the nucleus.
• D. It involves the emission of an electron or positron from the nucleus.

Answer: (D)

Verified step by step guidance

1. Understand that beta radiation involves the emission of beta particles, which are either electrons (beta minus) or positrons (beta plus) emitted from the nucleus during radioactive decay.
2. Recall that alpha radiation involves the emission of an alpha particle, which is a helium nucleus (He^{2+}), consisting of 2 protons and 2 neutrons, and this decreases the atomic number by 2.
3. Recognize that beta decay changes the atomic number by either increasing it by 1 (beta minus decay) or decreasing it by 1 (beta plus decay), but does not emit alpha particles.
4. Note that beta radiation always changes the atomic number by 1, so the statement that it does not change the atomic number is false.
5. Conclude that the true statement about beta radiation is that it involves the emission of an electron or positron from the nucleus.