3 DEFINITIONSMIXTURES- Mixtures are physical combinations of pure substances that have no definite or constant composition — the composition of a mixture varies according to who prepares the mixture. Mixtures are heterogeneous forms of matter. Mixtures are composed of variable proportions of molecules and atoms.
4 DEFINITIONSPURE SUBSTANCES- It has a definite and constant composition — like salt or sugar. A pure substance can be either an element or a compound, but the composition of a pure substance doesn’t vary. Some of the pure substances isolated from mixtures cannot be further broken down. Oxygen (O2) is an example.
5 PROPERTIES OF MIXTURES It can be separated into 2 or more substances by physical or mechanical meansIt displays the properties of the pure substances making it upIts composition can be varied by changing the proportion of pure substances making it upHeterogeneous substances, ones with non-uniform composition throughout the sample, are always mixtures
6 PROPERTIES OF PURE SUBSTANCES It can be separated into 2 or more substances by physical or mechanical meansIt is homogeneous, i.e, has uniform composition throughout the whole sampleIts properties are constant throughout the whole sampleIts properties do not depend on how it is prepared or purifiedIt has constant chemical composition