Year 4 investigates how materials change states through melting. 

This week, Year 4 launched an exciting new science topic: States of Matter. Building on our previous learning about what matter is and the three states of matter—solid, liquid, and gas—we continued to explore how particles behave in each state. We reminded ourselves that in a solid, particles are packed tightly and cannot move around, while in a gas, particles are spread out and move freely. These ideas helped us take the next step in our investigation: Melting – how do materials change state?

To start, we reviewed the differences between solids and liquids. Instead of just talking about it, we acted it out! When we pretended to be solid particles, we stood close together and stayed still. As liquid particles, we loosened up, moved more freely, and flowed around the room. This helped us clearly understand what happens when a solid melts and becomes a liquid.

Next, we carried out a hands-on investigation to find out how different materials melt and at what temperature the melting begins. Our materials were everyday items: butter and chocolate. We set up three bowls of water at different temperatures—cold, warm, and boiling. In each bowl, we placed the same amount of butter or chocolate on a piece of tin foil floating above the water. Then, using a thermometer, we watched carefully to see when the melting started. This links to our science vision of:

Be academic.

Be curious.

Be practical. 

We recorded the exact temperature at which each material began to soften and turn into a liquid. Once all the results were gathered, we compared the data and discussed our findings.

From our investigation, we learnt that materials melt at different temperatures, and the hotter the environment, the faster the melting happens. Butter and chocolate do not melt at the same point—showing that every material has its own melting point.

This investigation helped us understand that melting is a change of state caused by heat. It also reminded us how important particles are in explaining scientific ideas. Year 4 are now well on their way to becoming expert materials scientists!