Which one of the following contains a $P-O-P$ bond?

Give the preparation of phosphine $(PH_{3})$. State the physical and chemical properties of phosphine $(PH_{3})$. State the uses of phosphine.

Nitrogen dioxide is dissolved in water to produce

Which of the following substances is a deliquescent ionic solid?

Ionic radius (in $\mathring{A}$) of $As^{3+}$,$Sb^{3+}$ and $Bi^{3+}$ follow the order:

Which of the following compounds can exist?