Weathering

Chalk is a sedimentary rock made of the shells of tiny organisms. It forms organically as the shells of the organism accumulate on the ocean floor. When you write your name using chalk, it is actually undergoing physical weathering. Physical weathering breaks the rocks into smaller pieces without any chemical change. In this Warm-Up, you will observe what happens when chalk undergoes a different type of weathering: chemical weathering.

Equipment and Materials

• A piece of chalk
• A clear glass, beaker, or Erlenmeyer flask
• 16 ounces of water or vinegar

Procedure

1. Place the piece of chalk in the glass, beaker, or Erlenmeyer flask.
2. Fill the glass, beaker, or Erlenmeyer flask with enough of the water or vinegar to cover the chalk.
3. For three minutes, observe what happens to the chalk in the glass, beaker, or Erlenmeyer flask.