Question

Which is true about stable isotopes?
A. Isotopes are always unstable because they are radioactive.
B. A stable nucleus has a similar number of protons and neutrons.
C. Isotopes that are naturally occurring in nature are always unstable.
D. Isotopes with more neutrons than protons are always stable.

Answer 1

The correct statement about stable isotopes is:

**B. A stable nucleus has a similar number of protons and neutrons.**

Here's a brief explanation of each option to clarify why the others are incorrect:

A. **Isotopes are always unstable because they are radioactive.**
- This is false because isotopes can be stable or unstable. Stable isotopes do not undergo radioactive decay.

C. **Isotopes that are naturally occurring in nature are always unstable.**
- This is false; many naturally occurring isotopes are stable. For example, carbon-12 is a stable isotope.

D. **Isotopes with more neutrons than protons are always stable.**
- This is false; while some isotopes with more neutrons than protons can be stable, many of them are unstable and radioactive (e.g., carbon-14).

Thus, option B is the statement that is generally true regarding stable isotopes.