B for Buoyancy
The first time the little boy heard this term ‘Buoyancy’ was from a science book we read from Vooks. Since then, he has been experimenting dropping several objects in water and observing how they behave. Here’s one classic and amusing buoyancy experiment to demonstrate buoyancy.
Tips to introduce
- Be as creative as you can in introducing the concept to kids! First, you can begin talking about things that float like boats or your latest swimming experience.
- This buoyancy experiment might require children to understand the relationship between an object’s weight and the relation to its behavior in water. You may want to direct them to play by dropping objects in water for a few days before you come to this experiment.
- When you think they are ready for this experiment, write down on a sheet the things you’ll need and direct them to collect it all at one place. You may want to get the egg by yourself if they are too small to handle it. Fix a time and place and let them know you’ll meet them there, then.
- When you are at the experiment venue, explain to them what you are going to do without revealing what you are likely to observe.
- Set it up and let them observe what happens. Allow them to explain their inference if it is of their interest. Don’t push or annoyingly try to bring explanations out of them. Most importantly, enjoy if their rationales are not logical or correct. They are still children, and being right is not as important as being interested to observe and have fun with science. And then follow their cues to build on.
Things you’ll need
How do you do it?
1. Gently drop the egg inside the glass of water. If the egg is in good form, it will likely sink.
2. Using a spoon, remove the egg from the glass.
3. Now, add 3 to 5 spoons of salt into the glass of water and stir to dissolve the salt well.
4. Gently drop the egg again.
5. Observe what happens.
The Science behind
When an object is placed inside water/solution, the object displays a tendency to move towards the bottom, while water poses an upward opposing force on the object. Whether the object will float or sink depends upon the relative densities of the object and its surrounding solution.
When the egg is dropped in plain water, the force that water requires to push the egg upward is relatively lesser than the force the egg is thrusting upon water downward. Upon adding salt, as the weight of the salt is added to water, the force to keep the egg afloat is raised.
Share your experience
Was the buoyancy experiment helpful? Was it fun? Was it utter boring? Did it work? Or didn’t? Leave a word in the comment section. I would love to hear!
Here’s the full list of DIY Science Experiments in this series:
A for Air – Does Air has Weight?
B for Buoyancy – Can Egg float on Salt Water?
C for Capillary action – Rainbow Walking
D for Density – 3 Layer Density Experiment
E for Earth & Moon – Why does the Moon change its shape?: Phases of the Moon
F for Fire – Does Fire need Oxygen to Burn?
G for Gravity – Defying Gravity