the idea that all objects are made of tiny particles that are in constant motion

the higher the temperature of an object, the faster its particles move and the hotter it is

Mixing substances of different temperatures

Science

In the Particle explanations of density and pressure unit, they will build on this knowledge to learn how the arrangement and movement of particles in solids, liquids and gases explain density, pressure, floating and convection.

In the Solids, liquids, gases and changes of state unit, pupils learnt to categorise solids, liquids and gases, how the particles are arranged and moving in each state and what happens to particles during a change of state.

This unit explains energy transfer between objects due to temperature differences, through conduction or radiation, the role of insulators, and thermal equilibrium. It covers particle arrangements and motions in solids, liquids, and gases and Brownian motion.

Heating and cooling

50 cm³ of water at 80°C is mixed with 50 cm³ of water at 40°C. What will be the resulting temperature of the mixture?

100 cm³ of water at 60°C is mixed with 50 cm³ of water at 30°C. What will be the resulting temperature of the mixture?

100 cm³ of water at 80°C is mixed with 300 cm³ of water at 40°C. What will be the resulting temperature of the mixture?

What word describes the directions in which particles of water move in the liquid or gas state?

On average, the particles of the solid slow down.

On average, the particles of the solid speed up.

On average, the particles of the liquid slow down.

On average, the particles of the liquid speed up.

What happens when faster moving particles of a hot solid collide with slower moving particles of a cold liquid?

Particles of the lemonade cause particles of the water to break apart.

Particles of the lemonade cause particles of the water to melt.

Particles of the lemonade cause particles of the water to move faster.

Particles of the lemonade cause particles of the water to shrink.

Why does a cube of solid water (ice) melt when it is put into a glass of lemonade at room temperature?

A rectangular block of steel has a length of 8 cm, a width of 4 cm and a height of 3 cm. What is the volume of the block in cm³?

Which of the following pieces of equipment can measure the volume of a liquid most precisely?

In which state of matter do the particles in water move the fastest?

close together with spaces between each one

How close together are the particles of a liquid?

They move at the same speed and spread further apart.

They move more quickly and spread further apart.

What happens to the particles that make up a gas when it is heated to a higher temperature? 

Its particles transfer energy to your skin so quickly they damage skin cells.

Its particles are moving around so quickly they damage skin cells.

Its particles are spreading out so quickly they damage skin cells.

Why would touching a very hot piece of solid metal burn your skin?

This lesson will be removed by end of Summer Term 2025.

Mixing substances of different temperatures

Lesson outcome

This lesson will be removed by end of Summer Term 2025.