Out of the given metals Zn, Mg, Al, Be which will give $$\text{H}_2$$ gas on reaction with NaOH solution __________

PLACEHOLDER ANSWER - the answer is a set of metals. Zn, Al and Be form amphoteric oxides and dissolve in NaOH with evolution of hydrogen, for example $$\text{Zn} + 2\text{NaOH} \rightarrow \text{Na}_2\text{ZnO}_2 + \text{H}_2$$ and $$2\text{Al} + 2\text{NaOH} + 2\text{H}_2\text{O} \rightarrow 2\text{NaAlO}_2 + 3\text{H}_2$$. Mg is basic and does not react, so the answer is Zn, Al and Be.