Particle Theory of Matter (4 Principles) 1. All matter is made of tiny particles 2. All particles of a pure substance are the same. Different substances are made of different particles.

3. Particles are always moving 3. Particles are always moving. The more energy they have the faster they move. 4. There are attractive forces between particles. These forces are stronger when the particles are closer together.

Pure substance- A substance that contains only one type of particle Pure Substances vs. Mixtures Pure substance- A substance that contains only one type of particle Mixture- A grouping of more than one type of substance

Pure Substances Compound A molecule that contains two or more different elements Element A pure substance that can not be broken down into a simpler substance Molecule The combination of two or more atoms in a compound or element

Mixtures Heterogeneous Mixture A mixture in which the different components are visible and they can be separated physically Homogeneous Mixture (Solution) A mixture in which the different components are not visible

Hints Elements in Substance Type of substance Description Element A alone Pure substance (element) Only Element A is visible Elements A and B Pure substance (compound) The compound may have completely different properties from each of the elements. The elements are chemically combined. Mixture (homogeneous) The solution may look very similar to one of the elements, as particles of the other substance are hidden within it Mixture (heterogeneous) Particles of each element can be seen separately