Changing States: Melting and Freezing (Part 3)

What You'll Learn

Physical changes alter the appearance of matter without changing its chemical identity. Cutting paper, melting ice, and dissolving sugar are all physical changes.

Key Words

proton
neutron
electron

Materials Needed

baking soda
cups
spoons
food coloring
plastic bottles
balloons

Safety First

Wash hands after handling materials.
Be careful with scissors — ask an adult for help if needed.
Do not look directly at the sun or bright lights.

Steps

Step 1 — Read

Review the background information on Matter and Atoms before starting.

Step 2 — Do

Heat ice and record the temperature every minute as it melts and then boils. Graph the temperature changes and label each phase change.

Step 3 — Observe

Look for patterns in your observations.

Step 4 — Record

Make a graph or chart showing your results.

Check Your Understanding

Question 1

1 of 3

Which is an example of a chemical change?