What are compounds? Learning objectives: Explain what is meant by compounds Recognise how compounds form Understand how elements form compounds Starter: Make two lists 1 Mixtures 2 Elements Fill in as many mixtures and elements you know

Can you describe what a compound is? What is an element?? What is a mixture? Can you describe what a compound is?

Atoms in elements and compounds Elements are materials made up of one type of atom only. The element, hydrogen, exists as molecules. Each hydrogen molecule is made up of two hydrogen atoms joined together. H Compounds contain two or more different types of atom. The compound, water, exists as molecules. Each water molecule consists of two hydrogen atoms joined to one oxygen atom.

Properties of a compound – carbon dioxide A compound has different properties to the elements from which it is made because the atoms are joined differently. carbon oxygen carbon dioxide + Black solid used as fuel. Colourless gas in which many substances burn. Colourless gas used in fizzy drinks and fire extinguishers. + + O C

A compound is not a mixture The atoms in a mixture of hydrogen gas and oxygen gas, which have not reacted with each other, look like this… The atoms in water, the compound made when hydrogen and oxygen react and their atoms become chemically joined to each other, look like this…

Making compounds by heating mixtures Practical: Making compounds by heating mixtures Watch the demo carefully- think of the safety points

List all the safety points

Element 1 Iron Magnesium Copper Element 2 Oxygen ________ Sulphur We can make compounds from elements The name of the compound can tell us what elements have combined Element 1 Iron Magnesium Copper Element 2 Oxygen ________ Sulphur Compound Iron Oxide Magnesium Oxide Copper Sulp______

Method: Light a Bunsen burner and use a blue flame. Using a metal spatula drop a few drops of iron into the top of the flame. Using tongs, burmn1cm piece of magnesium in the flame. Safety: do not look directly at the burning magnesium. Complete the table. Number Name of compound Any changes you saw 1 Iron oxide 2 Magnesium oxide

Word splat Write down any keyword from the topic Write a question that the key word is the answer Word splat