A saturated solution is a solution in which no more solute can be dissolved in solvent without heating the solution.

The space between molecules in the three states of matter follow the order: Solid < Liquid < Gas

The molecules in gas have faster movement as compared to solids. Dry ice is solid carbon dioxide. It releases carbon dioxide gas and hence the molecules coming out move faster.

Water molecules in a liquid state only move around a little bit and not as much as the molecules in gas. In gaseous state the spaces between the molecules is maximum.

When liquid water is heated, the distance between the particles increases. This turns liquid water into a gaseous state called vapour.

A compound is a chemical substance which consists of more than one type of elements. Water is made up of two elements: oxygen and hydrogen.

Element is a substance which has same type of atoms. From given options Nitrogen is the only element.