Matter- Anything that has mass and volume and takes up space 2.1 Describing Matter Matter- Anything that has mass and volume and takes up space Different forms of matter have different properties that allow you to identify it.

Identifying Substances 2.1 Identifying Substances A physical property is a quality or condition of a substance that can be observed or measured without changing the substance’s composition. Hardness color boiling point/melting point conductivity, texture, magnetic attraction malleability

Ex. Mass, volume, length ect…. 2.1 Describing Matter Extensive Properties An extensive property is a property that depends on the amount of matter in a sample. Will change as the size of the sample changes Ex. Mass, volume, length ect….

Ex. Temperature, color, molecular weight, density ect… 2.1 Describing Matter Intensive Properties An intensive property is a property that depends on the type of matter in a sample. Doesn’t change when you alter the size of a sample Ex. Temperature, color, molecular weight, density ect… Doesn’t matter how much water you have temp, color,density will not change This bowling ball and candlepin are used in a game played mainly in New England

2.4 Chemical Changes CHEMICAL PROPERTIES The ability of a substance to undergo a specific chemical change is called a chemical property. Chemical properties can be used to identify a substance. But chemical properties can be observed only when a substance undergoes a chemical change. Ex. Flammability, reactivity, rusting

REVIEW Label the following properties as intensive or extensive and if they are a physical or chemical property Density Color Mass Malleability Combustibility

2.1 States of Matter States of Matter What are three states of matter?

A solid is a form of matter that has a definite shape and volume. 2.1 States of Matter Solids A solid is a form of matter that has a definite shape and volume. The arrangement of particles is different in solids, liquids, and gases. In a solid, the particles are packed closely together in a rigid arrangement.

2.1 States of Matter Liquid A liquid is a form of matter that has an indefinite shape, flows, yet has a fixed volume. The arrangement of particles is different in solids, liquids, and gases. In a liquid, the particles are close together, but they are free to flow past one another.

2.1 States of Matter Gases A gas is a form of matter that takes both the shape and volume of its container. The arrangement of particles is different in solids, liquids, and gases. In a gas, the particles are relatively far apart and can move freely. Relating Cause and Effect Use the arrangements of their particles to explain the general shape and volume of solids and gases.

Physical Changes 2.1 How can physical changes be classified?

2.1 Physical Changes During a physical change the composition of the material does not change. As gallium melts in a person’s hand, the shape of the sample changes, but the composition of the material does not change. The silvery substance in the photograph is gallium, which has a melting point of 30°C. Inferring What can you infer about the temperature of the hand holding the gallium?

Physical changes can be classified as reversible or irreversible. 2.1 Physical Changes Physical changes can be classified as reversible or irreversible. All physical changes that involve a change from one state to another are reversible. Cutting hair, filing nails, and cracking an egg are examples of irreversible physical changes.

During a chemical change, the composition of matter always changes. 2.4 Chemical Changes During a chemical change, the composition of matter always changes. Recall that during a physical change, the composition of matter never changes.

2.4 Chemical Changes A magnet separates iron from sulfur. This is an example of a physical change. A mixture of iron filings and sulfur can be changed. a) A magnet separates the iron from the sulfur. b) Heat combines iron and sulfur in a compound. Classifying Which change is a chemical change? Explain.

2.4 Chemical Changes A mixture of iron and sulfur is heated. The iron and sulfur react and form iron sulfide. This is an example of a chemical change. A mixture of iron filings and sulfur can be changed. a) A magnet separates the iron from the sulfur. b) Heat combines iron and sulfur in a compound. Classifying Which change is a chemical change? Explain.

A chemical change is also called a chemical reaction. 2.4 Chemical Changes A chemical change is also called a chemical reaction. One or more substances change into one or more new substances during a chemical reaction. A substance present at the start of the reaction is a reactant. A substance produced in the reaction is a product.

Recognizing Chemical Changes 2.4 Recognizing Chemical Changes Possible clues to chemical change include: a transfer of energy a change in color the production of a gas the formation of a precipitate.

Clues to chemical changes have practical applications. 2.4 Chemical Changes A precipitate is a solid that forms and settles out of a liquid mixture. Clues to chemical changes have practical applications. Clues to chemical change often have practical applications. a) Bubbles of carbon dioxide gas form when a geologist puts acid on a rock that contains compounds called carbonates. b) When a test strip is dipped in urine, the color change is used to estimate the level of the sugar glucose in urine. c) One step in the production of cheese is a reaction that causes milk to separate into solid curds and liquid whey.