Which of the following materials fall into the category of “pure substance”?


(a)Ice

(b)Milk

(c)Iron

(d)Hydrochloric acid

(e)Calcium oxide

(f)Mercury

(g)Brick

(e)Wood

(f)Air.

Pure substances : Iron, Ice, Hydrochloric acid, Calcium oxide, Mercury

Pure substances are substances that are made up of only one kind of particles and has a fixed or constant structure. Pure substances are further classified as elements and compounds. An element is a substance that consists of only one type or kind of atom. A compound is a material formed by chemically bonding two or more chemical elements.