Q. Consider the following pairs: - Gallium → Melts at near room temperature
- Mercury → Only metal liquid at room temperature
- Tungsten → Highest melting point among metals
- Francium → Longest-lived alkali metal isotope
Which of the above pairs are correctly matched?
Answer:
1, 2, and 3 only
Notes: Gallium melts at 29.7°C, so it can melt near room temperature. Mercury is the only metal liquid at room temperature. Tungsten has the highest melting point among metals. Francium is highly unstable and has very short-lived isotopes, making statement 4 incorrect.