Describing MatterSection

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Chapter

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What is Matter?

Matter is anything that has mass and takes up space.

http://videos.howstuffworks.com/hsw/8682-states-of-matter-solids-video.htm

What is ChemistryWhat is Chemistry

What is a substance?

Chemistry is the study of the properties of matter and how matter changes.

A substance is a single kind of matter that is pure.

Meaning, that it always has a specific makeup—or composition—and a specific set of properties.

Properties/Characteristics of Matter

PHYSICAL•Luster (shine)•Hardness•Texture•Shape•SizeCHEMICAL•Flammability•Color•Temperature

Examples of Physical Characteristics

Properties of MatterProperties of Matter

• Physical PropertyPhysical PropertyExample: A physical property of Example: A physical property of oxygen is that it is a gas at room oxygen is that it is a gas at room temperature.temperature.

• Chemical PropertyChemical PropertyExample: A chemical property of Example: A chemical property of oxygen is that it reacts with iron to oxygen is that it reacts with iron to form rust.form rust.

Every form of Every form of matter has two matter has two kinds of kinds of properties: properties:

1)1) physicalphysical2) chemical2) chemical

Changes in Matter:Physical vs. Chemical Change

- Change in state (i.e., boiled water)

- Separate parts of a substance (i.e., strained pulp from juice)

- Appearance (i.e., crushed can)

Physical Changes

Altered in form but not identity.

Examples in alterations:

Characteristic Properties of Matter

• Characteristic properties hold true for a given substance and never change.

• Since characteristic properties never change, they can be used to identify unknown matter.

Characteristic properties of matter never change.

Physical Properties:Characteristic Properties

1. Solid

2. Liquid

3. Gas

• Melting Point. The temperature at which a solid becomes a liquid.

• Solids become liquids at different temperatures.

• Ice melts at 0°C.http://videos.howstuffworks.com/hsw/8687-states-of-matter-changes-in-state-video.htm

• Boiling Point. The temperature at which a liquid boils.

• Different liquids boil at different temperatures.

• Water boils at 100° C.

Physical Properties:Characteristic Properties

Room Temperature20°C = 68°F.

Take the °C.1. Multiply by 1.8. 2. Add 32. The result is °F.

Look at the melting points (MP) and boiling points (BP) of the five substances. Identify each substance’ s physical state at room temperature (°C) .

Is it solid, liquid, or gas? Explain your conclusion.

Substance MP BP

Water 0 100Chloroform -64 61Ethanol -117 79Propane -190 -42Salt 801 1465

Chemical Changes

A chemical change occurs when one or more new substances is formed.

1. Made of same elements as original substances.

2. Elements are in different combinations than in original substances.

• Elements may combine to make compounds.

• Compounds may be broken down into elements.

• Compounds may change into other compounds.http://

videos.howstuffworks.com/hsw/8685-states-of-matter-chemical-changes-video.htm

Chemical Changes

Examples.

Rusting – turns iron into iron oxide.

Tarnishing – black residue on silver.

Chemical changes are the same as chemical reactions.

Burning – wood combines with oxygen to make carbon dioxide and water.

Explosion.

Chemical Changes

Stop Here.

Types of Matter:Pure Substance vs. Mixture

Matter is classified into two general categories.

Pure Substance• Element• Compound

Mixtures (Combination of pure substances.)• Heterogeneous• Homogeneous

Pure Substance: Elements

• Only a few more than 100 elements exist. Elements that cannot be broken down into simpler substances.

• You come in contact with only 30-40 elements in your daily life.

• Examples: Carbon, Chlorine, Copper, Nitrogen(Periodic Chart)

Element. A pure substance that cannot be broken down into other substances by any physical or chemical means.

Pure Substance: Compounds

A compound may be represented by a chemical formula, which shows the elements in the compound and the ration of atoms.

When elements are chemically combined, they form compounds having properties different from those of the uncombined elements.

Chemical Formula

Examples: NaCl (table salt):1 Sodium (Na)1 Chloride (Cl)

CO2 (carbon dioxide) 1 Carbon (C) 2 Oxygens (O)

1. Each substance in a mixture keeps its individual properties.

2. The parts of a mixture are not combined in a set ratio.

Example: Salt water.

Mixtures

All matter is composed of one element or a combination of different elements.

Mixtures differ from compounds in two ways:

How are pure substances related to mixtures?

Use the graphic organizer “Concept Map” for matter.

How can a pure substance be a compound and still be ‘pure’?

Question:

In a pure substance, whether element or compound, all the particles that make up the substance are the same, although each particle may be a combination of different particles. In a mixture, the particles that make up the substance will be different.

Answer: