Which ions are responsible for the chemical properties of bases in their aqueous solution?

What type of substance is $NH_{3}$?

$A$ substance $X$, which is an oxide of a group $2$ element, is used intensively in the cement industry. This element is present in bones also. On treatment with water, it forms a solution which turns red litmus blue. Identify $X$ and write the chemical reactions involved.

Which of the following are present in a dilute aqueous solution of hydrochloric acid?

Under what soil condition do you think a farmer would treat the soil of his fields with quick lime $(CaO)$,slaked lime $(Ca(OH)_2)$,or chalk $(CaCO_3)$?

$(i)$ Give an example of a strong base and a weak base.