This term, we will be covering the Year 5 chemistry strands of the National Curriculum and learn ab out Properties and changes of materials. 

During this unit of work, children will consolidate previous learning by revisiting the properties of solids, liquids and gases; learn to describe the properties of materials using scientific language; investigate which materials make the best thermal insulators; and which materials are magnetic. Children will be introduced to key scientific vocabulary to describe the properties of materials (e.g. soluble and insoluble) and investigate how to separate materials using these properties. They will be able to name separation methods (filtering, sieving, evaporation, magnets) and decide on the most efficient method for separating a mixture of materials.

Key objectives:

• Compare and group everyday materials based on their properties, including their hardness, solubility, transparency, conductivity (electrical and thermal), and response to magnets.
•  Know that some materials will dissolve in liquid to form a solution, and describe how to recover a substance from a solution.
• Use knowledge of solids, liquids and gases to decide how we might separate mixtures, including through filtering, sieving and evaporating.
• Give reasons, based on evidence from comparative and fair tests, for the particular uses of everyday materials, including metals, wood and plastic.
• Demonstrate that dissolving, mixing and changes of state are reversible changes. • Explain that some changes result in the formation of new materials and that this kind of change is not usually reversible.

Key Vocabulary

soluble - a substance that will dissolve in water

insoluble - a substance that will not dissolve in water

saturation - the point at which no more solute can be dissolved

solution - a soluble solid is dissolved in liquid to form a solution

filtration - the collection of larger particles in a mixture

boiling - the process by which molecules of a liquid change to vapour (much faster change than evaporation)

condensing - the change of vapour into a liquid

evaporation - change from a liquid to a vapour

freezing - the change of a liquid to a solid

melting point - the point at which a solid substance liquefies

chemical change - one where the molecular structures of the combined substances are broken down and recombined to make a new substance

physical change - where the molecular structures of the combined substance stay separate, allowing separation to occur reversible change - a physical change that we can undo

irreversible change - a physical change that we cannot undo