Weathering: Breaking Down Rocks

What You'll Learn

The rock cycle shows how rocks change from one type to another. Igneous rocks form from cooled magma, sedimentary rocks form from compressed sediment, and metamorphic rocks form under heat and pressure.

Key Words

evaporation
condensation

Materials Needed

rocks
sand
clay
water
plastic tray

Safety First

Handle glass items carefully to avoid breakage.
Do not mix unknown chemicals together.
Tie back long hair before starting the experiment.

Steps

Step 1 — Read

Read the introduction and identify the main idea of this lesson.

Step 2 — Do

Test rock hardness using Mohs scale: try scratching rocks with your fingernail, a penny, and a nail. Rank them from softest to hardest.

Step 3 — Observe

Use your senses (except taste) to describe what you notice.

Step 4 — Record

Write a summary of your findings in 3-5 sentences.

Check Your Understanding

Question 1

1 of 3

What causes weathering?