Unit 4

Matter Matter is anything that has mass and takes up space Matter is anything that has mass and takes up space

Homogeneous matter: uniform throughout – elements/compounds (substances) or solutions (mixtures).

Heterogeneous matter: not uniform throughout - *most mixtures (ex: salad, soil, chex mix, granite)

Classifying Matter Pure Substances: composition is the same throughout Pure Substances: composition is the same throughout

Elements cannot be chemically decomposed Compounds: two or more elements chemically combined C Ba K NaCl H 2 O

Mixtures Mixtures Two or more substances physically combined Two or more substances physically combined Homogeneous: solutions (ex: salt water, air) (look for (aq)) Homogeneous: solutions (ex: salt water, air) (look for (aq)) Heterogeneous: you can pick out the parts Heterogeneous: you can pick out the parts

Matter Can it be separated by physical means? YesNo Can it be separated by chemical means? Yes No Is it uniform throughout? Yes No Compound Element Homogeneous (aq) solution Heterogeneous

Phases of Matter

Gas: substances with no shape, no volume. *Takes the shape or volume of the container. Gas: substances with no shape, no volume. *Takes the shape or volume of the container.

Liquid: substances with a definite volume but no definite shape. Liquid: substances with a definite volume but no definite shape.

Solid: substances with definite shape and volume. Solid: substances with definite shape and volume.

The phase in which a substance exists is dependent upon the bonding between the particles. The stronger the bond, the more likely the substance can exist in the solid phase. The phase in which a substance exists is dependent upon the bonding between the particles. The stronger the bond, the more likely the substance can exist in the solid phase.

Physical Properties – any property that is observable and measurable. Color, texture, taste, smell, density, boiling point, melting point

Chemical Properties – the way a substance interacts with other chemicals – not observable or measured. Can’t see, touch or often predict. NaCl in H 2 O vs. Na in H 2 O

Physical Changes – any change in a physical property. It’s still the same substance – no chemical change. Ripping paper, crushing a dry leaf, boiling or freezing water.

Chemical Changes – Any change in a chemical property. Creates a new substance with new properties. Cooking an egg, burning paper

Phase changes--all physical changes Solid Liquid Gas

Solid to Liquid- Melting/Fusion Liquid to Solid- Freezing/Solidification Liquid to Gas – Evaporation/Boiling Gas to Liquid- Condensation Solid to Gas - Sublimation Gas to Solid - Deposition

Law of Multiple Proportions – the ability to make different compounds in different proportions using the same elements. H 2 O vs H 2 O 2 CO vs CO 2