Matter

What is matter? Has mass Like a rock is an idea matter? Takes up space Like air or water is heat matter?

Matter CCan it be physically separated yes no mixture Pure substance Uniform composition? yes no Homogeneous mixture Heterogeneous mixture Can be chemically separated yes no compoundelement

Physical separation methods Filtration – process that separates materials based on size Distillation – process that separates substances in solution based on their boiling points Chromatography -

Mixtures Homogeneous: evenly mixed cannot see individual parts solution example: salt water Heterogeneous: can see individual parts example: granite rock

Solution Systems gas-gas: Air Gas-liquid: Soft drink Liquid-gas Moist air Liquid –liquid Vinegar Solid-solid Steel (an alloy)

Pure Substances Elements: Composed of identical atoms Examples – copper, hydrogen Compounds: Composed of 2 or more elements in a fixed ratio Has different properties than constituent elements Examples: table salt (NaCl)

Changes in state of matter solidliquidgas meltingvaporization freezingcondensation sublimation deposition

Solids have a definite shape and a definite volume. Liquids have and indefinite shape and a definite volume. Gases have a indefinite shape and an indefinite volume.

Particle movement and phase solid liquidgas

Particle movement and phase solid liquidgas Add heat

Physical Properties Can be observed or measured without changing the composition of the matter – Melting point, boiling point – Density – Solubility – Color – Malleable/ductile – Hardness – Conductivity – Viscosity – Odor

Physical Changes Changes of state: melting, freezing, condensation, etc… Drawing copper into a wire Desalinization The substance only changes size, shape or state – it does not become a different substance

Chemical Properties The ability of a substance to combine with or change into another substance – Reactivity – flammability A new substance is formed

Chemical Changes Combustion Rusting, tarnishing

Evidence of a chemical change 1.Color change 2.Production of a gas 3.Formation of a precipitate (a solid that forms and separates from a liquid) 4.Temperature change

Check for understanding indicate if the change is physical or chemical 1.Melting ice 2.Painting wood 3.Burning wood 4.baking 5.Breaking glass 6.Burning propane 7.Iron rusting

Temperature The average kinetic energy of the particles in an object Absolute zero – no particle movement; theoretically impossible Regardless of how cold an object is the particles that make up that object are moving. The warmer an object is the more the particles move; the cooler – the slower

Phase change diagram

Phase Change Diagram Triple point – the point that represents the temperature and pressure at which all three states can coexist Lines between phases – water can exist in both phases Critical point – the temperature and pressure above which water cannot exist as a liquid

Heating/cooling curve

Heating curve Diagonal lines are temperature ranges at which the substance exist as a solid, liquid or gas. The horizontal lines are temperatures at which the substance is melting or boiling. During a phase change the temperature of the substance is not changing.