Q. Consider the following statements regarding isotopes:

1. Isotopes have different physical properties.
2. Isotopes possess similar chemical properties.
3. Isotopes have similar physical quantities and different chemical properties.

Which of the above statements is / are correct?
Answer: Only 1 and 2
Notes: Isotopes are atoms of the same element with identical atomic numbers but different mass numbers. Their chemical properties remain similar because they have the same valence electron configuration, but they exhibit different physical properties due to differences in mass, which affects measurable traits like density and melting point. Hence, only statements 1 and 2 are correct.