The movement of particles from an area where there are lots, until there is a random distribution of particles throughout a medium.

Happens without a clear pattern, making it unpredictable.

The random movement of particles in a fluid, due to colliding with particles in the surrounding medium.

A medium is usually a liquid or gas that other substances can mix into or move through, enabling other substances to mix or interact.

A fluid is a substance that flows or takes the shape of its container.  Liquids and gases can be described as fluids.

Diffusion

Science

Pure substances

Mixtures: choosing equipment

Mixtures: equipment diagrams

Mixtures and solutions

Dissolving

Variables

Dissolving: scientific methods

Solubility: practical

Solubility: analysis

Saturated solutions

In the Separation Techniques unit, pupils will build on their knowledge of solutions to learn about methods for separating mixtures, including filtration, evaporation, distillation, and chromatography.

In the Solid, Liquid and Gas States and Changes of State unit, pupils learned to categorise substances into the solid, liquid or gas state and explored particle behaviour during changes of state.

This unit explores the concepts of pure substances, mixtures, and diffusion in liquids and gases. It emphasises accuracy, precision, and the use of appropriate techniques during investigations. The focus is on making predictions and recording reliable observations.

Solutions

Physical activity and equipment requiring safe use

Which word best describes when something happens without a clear, predictable pattern?

The random movement of particles due to collisions in a fluid is known as {{}} motion.

What is the name given to a material that other substances mix into or move through?

Jacob is sat in his first floor bedroom.  He can smell bread baking in the kitchen on the ground floor.  This is due to the process of {{}}.

Only the temperature of the medium will affect it.

Only the temperature of the diffusing substance will affect it.

The temperature of both the diffusing substance and the medium will affect it.

Temperature does not affect how quickly diffusion occurs.

Which of the following is a true statement about how quickly diffusion occurs?

Complete the 3 sentences describing what is happening in the picture: The ink and water particles are ____ moving. They ____ together and this causes them to mix. The ink will ____ through the water.

Which state of matter has particles furthest apart from each other?

The particles would collect on one side of the container.

The particles would sink to the bottom of the container.

The particles would spread to fill the container.

If a gas was placed into a container, what would you expect the gas particles to do?

are randomly moving and take the shape of the container

are randomly moving and have no fixed shape

two or more substances that can be physically separated

formed when a substance dissolves in a liquid

a substance which flows and can be a gas or a liquid

Match the following scientific keywords with the correct description.

What is the scientific term used to describe a substance whose particles can be pushed together into a smaller volume?

What is the correct working out to show how much solute was used with 145.63 g of water to create a solution with mass 147.59 g?

Diffusion

Lesson outcome

Content guidance