Elements, Compounds and Mixtures

Elements, Compounds and Mixtures

Elements

• An element is a substance made up of only one type of atom.

• There are about 100 naturally occurring elements, and they are listed in the Periodic Table.

• Each element has its own symbol, like ‘H’ for hydrogen and ‘O’ for oxygen.

• Elements can be metals or non-metals.

Compounds

• A compound is a substance made from two or more different elements that are chemically joined.

• The different atoms are held together by chemical bonds.

• The properties of a compound are different from the properties of the individual elements it is made of.

• Compounds can be broken down into simpler substances by chemical reactions.

Mixtures

• A mixture consists of two or more different substances mingled together but not chemically combined.

• Mixtures can be separated into their component parts using methods like filtering, evaporation, distillation, and chromatography.

• The properties of a mixture are just the combination of the properties of the substances it is made of.

Keywords to Remember

• Atom: The smallest unit of an element that retains the properties of that element.

• Molecule: Two or more atoms bonded together.

• Pure substance: Substances that are either elements or compounds.

• Chemical reaction: Process where new substances are formed from one or more substances.

Remember these key points and continue practising past paper questions to get familiar with the type of questions you may encounter. Always discuss any difficulties with your teacher.