$(i)$ Name a metal which does not stick to glass.
$(ii)$ Name the metal which is commonly used in thermite welding.
$(iii)$ What is the nature of zinc oxide?

(N/A) $(i)$ Mercury $(Hg)$ is a metal that does not stick to glass due to its high surface tension and weak adhesive forces with glass.
$(ii)$ Aluminium $(Al)$ is the metal commonly used in thermite welding because it acts as a strong reducing agent when reacting with metal oxides.
$(iii)$ Zinc oxide $(ZnO)$ is amphoteric in nature,meaning it reacts with both acids and bases to form salt and water.