During the extraction of iron from hematite in a blast furnace,which substance is obtained as slag?

Galvanisation is a method of protecting iron from rusting by coating it with a thin layer of:

Iqbal treated a lustrous,divalent element $M$ with sodium hydroxide. He observed the formation of bubbles in the reaction mixture. He made the same observations when this element was treated with hydrochloric acid. Suggest how can he identify the produced gas. Write chemical equations for both the reactions.

Which process is used to determine the reactivity of a metal?

Out of the $114$ elements discovered so far,how many elements do not behave as metals?

Explain the following statements:
$(a)$ Most metal oxides are insoluble in water but some of these dissolve in water. What are these oxides and their solutions in water called?
$(b)$ At ordinary temperature,the surfaces of metals such as magnesium,aluminium,and zinc are covered with a thin layer. What is the composition of this layer? State its importance.
$(c)$ Some alkali metals can be cut with a knife.