Unit 2 - Atoms and ElementsChapter 4 - Matter and the Natural World

Unit 2 - Atoms and Elements 1 / 8

4.1 - Investigating Matter

Fireworks demonstrate the brilliance of chemistry. Some substances burnwith bright colours when heated and others make loud crackling noises.

Unit 2 - Atoms and Elements 2 / 8

The different colours in fireworks:

Red: Compounds of lithium and strontium

Orange: Compounds of calcium and sodium

Green: Compounds of copper and barium

Electric White: Magnesium and aluminum metals

Watch: “London Fireworks 2014”

Unit 2 - Atoms and Elements 3 / 8

Forms of Matter

Matter is anything that has mass and takes up space.

Mass is a measure of the amount of substance in an object. Mass isusually measured in grams (g) or kilograms (kg).

Volume is a measure of how much space an object occupies. Volume isusually measured in millilitres (mL) or litres (L).

Unit 2 - Atoms and Elements 4 / 8

States of Matter

Solid: Has a definite, fixed shape and a fixed volume.

Liquid: Takes the shape of its container and has a fixed volume.

Gas: Takes the shape of its container and has an indefinite volume.

Plasma: Similar properties of gases.

Unit 2 - Atoms and Elements 5 / 8

Classifying Matter

Unit 2 - Atoms and Elements 6 / 8

Pure Substances

A pure substance is made up of only one kind of particle. Within puresubstances are two categories:

An element is made up of one type of particle that cannot besimplified or broken down (ex: oxygen, hydrogen, iron).

A compound is made from two or more elements (ex: water, tablesalt).

Unit 2 - Atoms and Elements 7 / 8

Mixtures

A mixture is a combination of pure substances. Each substance remainsin its original form. Within mixtures, there are two main categories:

Homogeneous mixtures (solutions): The different substances thatmake up the mixture are not individually visible (ex: iced tea).

Heterogenous mixtures: The different substances that make up themixture are visible (ex: italian salad dressing).

Unit 2 - Atoms and Elements 8 / 8