Elements, compounds and mixtures
Look at particle models of everyday substances, test whether they can be separated, and sort them into elements, compounds and mixtures.
Core concept
An element has one kind of atom, a compound has different atoms chemically joined in fixed amounts, and a mixture has substances mixed but not joined
Topic: Matter
An element is made of only one kind of atom, such as iron (Fe) or oxygen: A gas in the air that living things need to breathe and that fire needs to burn. All key words (O₂). A compound is made of two or more kinds of atom chemically joined in a fixed ratio, such as water (H₂O); it has new properties and can only be split by a chemical reaction. A mixture: Two or more substances mixed together, which can be separated again. All key words contains two or more substances that are mixed but not chemically joined, such as air or salt water. The amounts in a mixture can vary, and it can be separated by physical methods like filtration: Separating solid bits from a liquid by pouring it through filter paper or cloth. All key words, evaporating or using a magnet.
What you will learn
- Describe elements, compounds and mixtures using particle models.
- Explain the difference between a compound and a mixture.
- Classify everyday substances.
Before you start
- Know that matter is made of tiny particles called atoms.
Materials
- Iron nail, copper wire, charcoal, oxygen, water, salt, sugar, carbon dioxide, air, salt water, muddy water, brass
Equipment
- Particle model cards
Procedure
- Choose a card and look at its particle model.
- Check whether it can be separated by a physical method.
- Place each card in the elements, compounds or mixtures group.