Matter 2.3 Compounds and Mixture

Substances - matter that has the same compositions and properties Compound - a pure substance whose smallest unit is made up of atoms of more than one element Examples: water, Hydrogen peroxide, Carbon Dioxide Compounds need Formulas Subscripts refer to number of atoms No subscripts for one atom Law of Definite proportions - a given compound is always made of the same elements in the same proportion by mass.

Mixtures - two or more elements combined that don’t make a new, pure substance Examples: Air, Cereal, Blood Uniform mixtures - cannot see the individual parts Nonuniform mixtures - can see the different parts. 2.3 Pg 55 1-3