Q. Consider the following statements:

1. Selenium is a good conductor in the dark but an insulator in light.
2. Manganese is the least abundant transition element in Earth's crust.
3. Both gallium and germanium are liquid at room temperature.
4. Bromine is the only liquid non-metal at room temperature.

Which of the above statements is/are correct?
Answer: Only 4
Notes: Statement 1 is incorrect; selenium is a better conductor in light, not in dark. Statement 2 is incorrect; scandium is less abundant than manganese among transition elements. Statement 3 is incorrect; only gallium is liquid at room temperature, not germanium. Statement 4 is correct; bromine is the only liquid non-metal at room temperature.