Topic 1.1 Intro. to the particulate nature of matter

Matter has a mass occupies a volume in space made up of particles (atoms, molecules, or ions) particles are in constant motion page 2 in IB textbook TOK

Intermolecular forces States of Matter Solid Liquid Gas Spacing closest intermediate very far Shape fixed (lattice) bottom of container container Intermolecular forces strong weak Kinetic energy low high

State Change LIQUID vaporization* *evaporation *boiling melting condensation freezing deposition GAS SOLID sublimation = taking away heat (cooling down) = adding heat (heating up)

*Boiling vs. Evaporation-- in more detail the vapor pressure in the liquid is greater than the atmospheric pressure occurs throughout the liquid Evaporation opposite only occurs at the surface of the liquid

energy added at phase change goes into breaking inter-particle forces and NOT raising the temperature

Classifying Matter Matter Pure Substance Mixture Homogeneous Mixture Are all the particles alike? YES NO Pure Substance Mixture Are the particles one kind of atom? Are the particles well-mixed and mixed evenly? YES NO YES NO Homogeneous Mixture Heterogeneous Mixture Element Compounds or Molecules

Element a substance that cannot be broken down by chemical means into simpler substances examples- Al, H, Cu, Na, O… Compound two or more elements chemically bonded together H2O, NaCl, CO2, HCN…

Mixtures more than one element or compound that are not chemically bonded together and therefore retain their individual properties examples- salt water, air, dirt, metal alloys… homogenous mixtures uniform properties (all parts of the mixture are the same) heterogenous mixtures non-uniform properties (all parts of the mixture are not the same)

techniques to separate mixtures boil away liquids (fractional distillation) different liquids boil away at different temperatures use a magnet filter with funnel and filter paper paper chromotography manually with tools …

fractional distillation

Chemical vs. Physical Change a chemical change is the process of breaking of chemical bonds (ionic or covalent) in one or more substances, and then reforming of new bonds to create new substances a physical change is simply changing the state of matter, altering shape, size…