CHAPTER 3 Matter and Change

Section 3.1 Properties of Matter Matter is anything that has mass and takes up space. Matter is everything around us. Matter with a uniform and unchanging composition is a substance.

States of Matter The physical forms of matter, either solid, liquid, or gas, are called the states of matter. Solids are a form of matter that have their own definite shape and volume. Liquids are a form of matter that have a definite volume but take the shape of the container.

Gases have no definite shape or volume Gases have no definite shape or volume. They expand to fill their container. Vapor refers to the gaseous state of a substance that is a solid or liquid at room temperature.

Physical Properties of Matter A physical property is a characteristic that can be observed or measured without changing the sample’s composition.

Extensive properties are dependent on the amount of substance present. Examples??? Intensive properties are independent of the amount of substance present.

Chemical Properties of Matter The ability of a substance to combine with or change into one or more other substances is called a chemical property. Iron forming rust Copper turning green in the air

A substance can change form– both physically & chemically!!! Chemical properties can change with specific environmental conditions, such as temperature and pressure.

Section 3.2 Changes in Matter Physical Changes… A change that alters a substance without changing its composition is known as a physical change.

Phase changes are physical changes!!! Melting – s to l Freezing – l to s Evaporating/Boiling – l to g Condensation – g to l Sublimation – s to g Deposition – g to s

Chemical Changes… A change that involves one or more substances turning into new substances is called a chemical change. Decomposing, rusting, exploding, burning, or oxidizing are all terms that describe chemical changes.

A chemical reaction always produces a change in properties!!! Indicators of Chemical Change: color change temperature change odor produced gas or precipitate (solid) formed

Our 1st Scientific Law this year… The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction, it is conserved. The mass of the reactants equals the mass of the products. massreactants = massproducts Lavoisier, late 1700’s