PISAM! and the Classification of Matter

Particle Theory of Matter All matter is made of particles. The particles in a given substance are identical. There are spaces between the particles. The particles attract one another. The particles are moving (and when heat is added they move more).

Changes in State particles are very close strong attraction vibration only back and forth energy of motion is small compared to forces of attraction particles are close particles can slide past each other energy of motion is small compared to forces of attraction particles are very far apart particles are moving rapidly forces of attraction are almost zero compared to energy of motion

Changes in State melting sublimation freezing sublimation evaporation condensation

Changes in State Initial State Final State Change of State Heat added or removed solid liquid melting added gas sublimation evaporation freezing removed condensation

Classification of Matter Pure Substances Mixtures All particles are the same All particles are NOT the same Compounds Elements Solutions Heterogeneous Mixtures made of 2 or more elements can be broken down chemically -one phase E.g. carbon dioxide, sodium nitrate, water (i.e. dihydrogen monoxide) simplest form cannot be broken down -on the periodic table -one phase E.g. helium, carbon, oxygen, mercury looks like one substance (i.e. one phase) E.g. kool aid can see the parts (i.e. more than one phase) E.g. soup, pizza, oh henry

1. Element a pure substance that contains only one kind of atom (H,O,F,Br,I,N,Cl; are found in pairs, i.e. H2) 2. Compound a pure substance that includes two or more kinds of atoms stuck together one kind of molecule

3. Heterogeneous mixture a mixture where you can see the different compounds or elements. This is also known as a mechanical mixture. Example – vegetable soup 4. Homogeneous mixture mixture where you cannot see the different compounds or elements A solution is a homogeneous mixture. Example – chocolate milk

Solutions are made up of a solute and a solvent solute – part that is dissolved solvent – part that solute dissolves in Example - when salt is added to water it will dissolve and form a solution of salt water. salt - solute and water - solvent

Classification of Matter How to figure out what’s what: 1. Is it on the Periodic Table? (element) Does it have a chemical first and last name? (compound) Does it have 2 components but one phase? (solution) Does it have 2 components and 2 phases? (heterogeneous mixture) Exceptions: water, sugar and salt are all compounds

HOMEWORK Complete the page of particle diagrams