Matter and Change

Chapter 2

What’s a matter? (Chapter 2)

Matter – anything that has mass and occupies space Elements are the simplest forms of matter

Mass – amount of matter an object contains Substance – matter with a constant and

definite composition Substances combine to form mixtures and

compounds

Describing Matter

Properties used to describe matter can be classified as:

1) Extensive – depends on the amount of matter in the sample

- Mass, volume, calories are examples

2) Intensive – depends on the type of matter, not the amount present

- Hardness, Density, Boiling Point

Mixtures (2.2)

Mixtures are formed when 2 or more substances are physically combined Can be different states of matter

Homogeneous mixtures (or solutions) have a uniform composition

Heterogeneous mixtures have an uneven composition

Mixtures can be separated by physical means.

Compounds (2.3)

Compounds are made when two or more substances (elements) are chemically combined.

Compounds can only be separated by a chemical reaction.

The properties of compounds are different than their parent substances.

Matter Flowchart

States of Matter (2.1)

There are 3 main states of matter: Solids Liquids Gases

Each type of matter has a unique set of physical properties Shape Volume Compressibility

Physical & Chemical Properties (2.1/2.4)

Physical properties can be observed using your senses and without destroying the object Color, hardness, density…

Chemical properties indicate how a substance reacts with something else; in this case the original substance is fundamentally changed Flammability, rusting, combustion

Physical vs. Chemical Changes (2.1/2.4)

Physical change – a change in the form of a substance, but not in its chemical composition

Chemical change – when substances change into new substances through a rearrangement of the atoms, known as a chemical reaction

In a chemical reaction, reactants are the starting substances and products are the new substances formed.

ReactantsReactants ProductsProducts

Law of Conservation of Mass

Law of Conservation of Mass

Mass of the products = Mass of the reactants

If it appears that mass has been lost, look for evidence of a gas being released – gases have mass too!