Did you know that you can change the color of white flowers by placing them in a container with food coloring and water? That easy flower that changes color scientific experiment It's great to learn about perspiration and transport in plants.
Easy perspiration experiment
How to make color changing flowers
You will need to
White flowers
Food coloring: we have found Wilton Gel Colors work well. Natural food colors DO NOT work in our experience.
Water
Small jar or vase
Perspiration experiment – instructions
Cut the flowers by the stems.
Fill a vase or jar with water and add a little food coloring.
Place the flowers in the jar and let them rest for a few hours.
You will usually see the flowers change color within a few hours.
Additional Breathing Challenges
Try carefully splitting a stem in half with a sharp knife (ask an adult to do this)
Place half of the stem in one color of water and the other in another color. After a few hours, you should have a flower with two different colored petals!
What is perspiration?
The white petals change color due to something called transpiration stream. Transpiration is the movement of water through the stem of a plant from the root to the leaf when the plant loses water due to evaporation and diffusion of water from the plant surface. First, the root absorbs water and moves it through the root hair cells through the process of osmosis. It then passes into the xylem vessel, which is the tube that transports water through the stem. Water rises through the xylem vessel accession (being pulled towards the side of the ship) and cohesion (water molecules attract each other).
When water evaporates from the surface of the leaves, the change in pressure pushes the water column upward to replace the lost water. There is a constant flow of transpiration water through the plant.
The best way to think about this is to imagine that you have a thick milkshake: the straw cannot lift the milkshake on its own, but if you suck from above, the milkshake is sucked into the straw. It moves in a column because water molecules attract each other.
What affects the rate of perspiration?
The transpiration rate is affected by environmental factors.
Factors that affect perspiration.
Light
Transpiration is faster when there is more sunlight. Stomata (small pores on the surface of a plant) close when it is dark, as they do not need to be open when photosynthesis is not taking place. Photosynthesis also needs sunlight. When the stomata are closed, water cannot escape from the plant surface.
Temperature
Transpiration occurs at a faster rate at higher temperatures. In hot climates, water particles evaporate and diffuse through the stomata faster, increasing the transpiration rate.
Air movement around the plant.
When air flow around a plant is good, transpiration is faster as water vapor that has just diffused and evaporated from the leaf moves away, increasing the concentration gradient between the air and the inside of the leaf. . Diffusion is faster when the concentration gradient is more significant.
The effect of increased airflow in transpiration rate It can be demonstrated using celery, food coloring, water, and a hair dryer!
What food coloring should I use?
We have found that natural food colors don't work, but these gel colors from Wilton always work.
If you liked this experiment, don't forget to try my other one. plant science experiments.
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Last updated on May 7, 2024 by Emma Vanstone
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