Question

Question 2
Try segregating the things around you as pure substances or mixtures.

Answer 1

A pure substance is a material that has a constant composition (is homogeneous) and has consistent properties throughout the sample. A mixture is a combination of two or more pure substances in which each pure substance retains its individual chemical properties.

Pure substances: Water, iron nail, pencil lead, sugar,common salt, rubber etc.
Mixtures: Air, blood, butter, milk, steel, paper, wood, coal etc.