Changing States

The scene lets students explore an environment that can change the temperature of objects, such as ice cream, ice cubes, drinks, and air. The particle models within the objects will model how particles are arranged in the solids, liquids and gases, but importantly, how their arrangement can change when they lose or gain heat energy, leading to a change of state.

# Learning objectives

Be able to describe the states of matter using the particle model{.info}

Be able to describe change of states of matter using key terminology{.info}

Be able to Explain that change of states of matter occurs due to heat energy{.info}

# Melting{.objective .objective1}

In this section, the particle arrangement in solids will be described. Solids are typically arranged in a regular pattern in a fixed position, unable to move around, and only vibrate. Observing the animated particles in the scene should encourage a discussion to identify when the model represents a solid based on the particle arrangements.. Here, students should begin to describe what happens to particles as they gain heat energy and at which point they melt. Observations should conclude that particles vibrate faster until they break away from their regular arrangement and move around freely, yet remain closely packed, turning into liquids as the solid melts.

# Boiling{.objective .objective2}

In this section, the particle arrangement of liquids is described, and a comparison to solids should be encouraged. While liquids are closely packed, they are not in a regular fixed position and can move freely around each other. As such, liquids can flow and take their container's shape.. Students should give reasons for this, linking it to the heat energy gained by particles, which led to the solid melting. A discussion should allow students to think about what would happen if the liquid particles continued to gain more heat energy. Students should conclude that the liquid particles would gain enough energy, move faster, break away from the liquid state and evaporates as it changes into a gas once they reach the boiling point.

# Condensing and Freezing{.objective .objective3}

In this section, a description of the particle arrangement in a gas will be outlined. The spread-out arrangement allows gas particles to spread out, fill and occupy the space they are in. Here, students will explore what happens to particles when they lose heat energy and move more slowly. A discussion should be encouraged as students observe the animated change of state. A conclusion should be drawn towards particles moving closer to each other, eventually condensing into a liquid and freezing into a solid.

# Teacher Resources

### Download Teacher Notes

[](https://avnfs.com/nF9Vo42apzfYMYAMeIPhvPlXMUs8pLUO72P7wjpYAgs?size=1283017&type=application%2Fpdf&name=Changing+States+Teacher+Notes+1.pdf)

### Student Quiz Answers Document

[](https://avnfs.com/6wWYECUPjg5ZQGYwTfdtmWZ6X_tMwlooKMzxWEXblTw?size=622287&type=application%2Fpdf&name=Changing+States+Teacher+Notes+2.pdf)

### Download Student Quiz Document

[](https://avnfs.com/FDK7fYcR-t8S91Hr9vwAMoixGMwDdf09EAL9NVjujS0?size=94847&type=application%2Fpdf&name=Changing+States+Teacher+Notes+3.pdf)