Which of the following metals produces hydrogen gas when heated with hot concentrated alkali?

Which of the following is the weakest reducing agent?

Why are potassium and cesium,rather than lithium,used in photoelectric cells?

Statement $I$: An alloy of lithium and magnesium is used to make aircraft plates.
Statement $II$: The magnesium ions are important for cell-membrane integrity.
In the light of the above statements,choose the correct answer from the options given below.

How is $NaCl$ prepared from brine (sea water)?

The solution of sodium metal in liquid ammonia is a strong reducing agent due to the presence of...