Which gas is produced when zinc reacts with diluted hydrochloric acid?

Which metal ore can be concentrated by the magnetic separation method?

Two ores $A$ and $B$ were taken. On heating, ore $A$ gives $CO_2$, whereas ore $B$ gives $SO_2$. What steps will you take to convert them into metals?

What type of compounds are formed when reactive metals like sodium and potassium react with dihydrogen?

Which of the following metals is the least reactive?

$(a)$ List two differences between calcination and roasting in tabular form.
$(b)$ Which method will you use to reduce the following? Explain by giving a suitable example.
$(i)$ Oxides of less reactive metals.
$(ii)$ Oxides of moderately reactive metals.
$(iii)$ Oxides of highly reactive metals.