Discussing new concepts and practicing new skills #1 Activity 1: How does water break down rocks? Objective: Describe how water break down rocks. Materials: small and soft rocks, a jar half filled with water, piece of cloth, and rubber band Procedure: 1. Put the small and soft rock samples that you have prepared inside the glass jar half-filled with water then cover it tightly. 2. Shake the glass jar for about 2 minutes 3. Remove the cover of the glass jar. Replace it with the piece of cloth at the brim of the bottle with the use of the rubber band as shown on the right: 4. Turn the glass jar upside down to empty the water in the bottle as shown on the right. 5. When the water is gone, remove the piece of cloth in the glass jar and examine the rock sample that you placed inside. Guide Questions: 1. What happened to the rock samples that you have placed inside the glass jar? 2. Where did the small particles in the glass jar come from? 3. What caused the rock to break in small pieces? 4. Are these small particles look the same with soil?
The Correct Answer and Explanation is:
Correct Answers to Guide Questions:
- What happened to the rock samples that you have placed inside the glass jar?
The rock samples became smaller, and some of them broke into smaller pieces. - Where did the small particles in the glass jar come from?
The small particles came from the rocks that were broken down during the shaking process. - What caused the rock to break in small pieces?
The force of shaking the jar and the constant collision of the rocks with each other and the jar caused the rocks to break into smaller pieces. - Do these small particles look the same as soil?
Yes, the small particles look similar to soil because soil is partly made of tiny rock particles.
Explanation:
This activity demonstrates one of the main ways rocks break down in nature: through a process called mechanical weathering, specifically abrasion. When the jar is shaken, the rocks hit against each other and the sides of the jar repeatedly. This constant impact causes small pieces of the rock to break off. The longer and harder the shaking, the more the rocks wear down. This simulates how rocks are weathered in rivers and streams where they are rolled and rubbed against each other by moving water.
The small particles left in the jar after shaking are called sediments. These sediments are the broken-down fragments of the original rocks. In nature, these sediments can be carried by water and eventually settle in new places, forming layers that may one day become part of new rocks.
Over time, this process contributes to the formation of soil. Soil is made up of weathered rock particles, organic material (from plants and animals), air, and water. That is why the small particles in the jar may look like soil — they are similar in texture and composition to the mineral part of soil.
This simple experiment helps us understand how natural forces like water and motion slowly break down rocks over time, shaping the Earth’s surface and playing an important role in the rock cycle.
