Do differences in the sizes of leaves affect the rate of evaporation? Find out.
Things Required:
3 paper towel sheets
Waxed paper
Cookie baking sheet
Directions:
Dampen the paper towel sheets with water. They should be wet, but not dripping. Lie one paper towel flat on the baking sheet. Roll up a second paper towel and place it next to the flat one on the pan. Roll the last paper towel as you did the second one, but cover the outside of the roll with waxed paper. Secure the ends, top and bottom, of the waxed paper roll with paper clips.
Place the waxed covered paper roll on the baking pan. Position the pan with its paper rolls where it will receive direct sunlight. Unroll the paper after 24 hours and feel the paper.
This Is What Happens:
The flat towel is dry. The rolled towel is dry on the ends, but has damp spots inside. The waxed paper coated towel is damp all over.
Science Behind It:
The more surface area that is exposed to the air, the faster the water evaporates. The speed that the water evaporates is called the evaporation rate. Desert plants have thick and/or round leaves to help prevent water loss. The surface of the leaves is waxy, further restricting water loss. The shape, thickness and covering of a desert plant leaves causes them to have a very slow rate of evaporation.
