MatterChapter 2

Pages 58-81

Matter•Anything that has mass and takes up space

States of matter

The three states of matter are solids, liquids and gasses.

Characteristic Properties

• Regardless of state of matter, a substance has a unique characteristic property.

Elements

• Can’t be broken down into another substance.

•ELEMENTS

Compound

• Chemical Combination of elements.

• EX: H20water

CO2Carbon Dioxide

C12022H11 Sugar

C6H12O6 Glucose

Atom• The smallest particle of an element.

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Molecule

• A group of atoms joined together.

chocolate

• player_framemolecules.htm

Chemical Bond

• The force that holds the atoms together.

Formula• Ratio of atoms of each

element in a compound.

Theobromine, C7H8O4N2 or Chocolate

Law of Conservation of Matter

• Matter is neither created nor destroyed during a chemical change.

• It recombines to make a new type of chemical.

Pure Substance

• One kind of matter with no substances mixed in.

• EX. Sugar, gold, silver, salt.

Mixture

• When two or more substances are mixed together but have different properties.

EX: Salt Water

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Solution

• As well mixed as possible or when a substance has dissolved.

• player_frame2.htm

Changes in Matter

• Physical Change: When the state of matter changes.

Physical Change

• whipping egg whites (air is forced into the fluid, but no new substance is produced)

• magnetizing a compass needle (there is realignment of groups ("domains") of iron atoms, but no real change within the iron atoms themselves).

• boiling water (water molecules are forced away from each other when the liquid changes to vapor, but the molecules are still H2O.)

• dissolving sugar in water (sugar molecules are dispersed within the water, but the individual sugar molecules are unchanged.)

• dicing potatoes (cutting usually separates molecules without changing them.)

Changes in Matter cont…

• Chemical Change: When a substance(s) combine or decompose into a new substance.

Examples of a chemical change

iron rusting (iron oxide forms) gasoline burning (water vapor and carbon

dioxide form) eggs cooking (fluid protein molecules uncoil and

crosslink to form a network) bread rising (yeast converts carbohydrates into

carbon dioxide gas) milk souring (sour-tasting lactic acid is

produced) suntanning (vitamin D and melanin is produced)

Type of characteristic properties

• Boiling Points: The temperature at which a liquid boils.

Water's boiling point is 100 °C

Melting/Freezing Points

• Temperature at which a solid turns into a liquid.

Intermolecular forces (IMF’s):

These are forces that hold particles (molecules) together.

Energy and State Change

• When a substance changes state:

• Solid liquid gas = gaining energy

• Gas liquid solid = loses energy

Temperature affects state.

Substances with weak IMF’s become liquids and gasses at low temperatures.

In contrast, substances with strong IMF’s can stay in a solid state even at extreme temperatures. Substances with strong IMF’s become liquids and gasses at high temperatures.