What is formed when sulfur trioxide gas is absorbed in concentrated sulfuric acid?

Name two metals in each of the following cases:
$(i)$ Metals that are stored in kerosene.
$(ii)$ Metals that are alloyed with iron to make stainless steel.
$(iii)$ Metals which are highly malleable and ductile.

What is the number of electrons lost by a metal atom to form a positive ion called?

$A$ piece of $Zn$ metal cannot displace which of the following metal ions from its salt solution?

Why is sodium chloride soluble in water but not soluble in kerosene?

Write chemical equations for the reactions taking place when:
$(i)$ iron is strongly heated in air.
$(ii)$ lead carbonate is calcined.
$(iii)$ chromium oxide $(Cr_{2}O_{3})$ is heated with aluminium powder.