Which of the following substances is hygroscopic?

Why should metal sulphides and carbonates be converted to metal oxides during the process of metal extraction?

When a metal $X$ is treated with cold water,it gives a basic salt $Y$ with molecular formula $XOH$ (Molecular mass $= 40$) and liberates a gas $Z$ which easily catches fire. Identify $X, Y, Z$.

Which of the following metals exists in nature in liquid state?

Which process occurs at the anode during the process of electrolysis?

Name two metals which have very low melting points.