One day Xiaobian was eating chocolate while drinking soda
Who knew a hand-shaking chocolate was gone
Looking down, it actually floated in the cup and dangled
The foodie's desire to explore is not on fire!
Experimental equipment
Cup, sparkling water, beaker, chocolate, knife
Experimental process
First, we cut the chocolate into long strips
Then, throw it into a beaker filled with soda
After a while, a layer of bubbles will be attached to the surface of the chocolate
Three things can happen after that:
1. Larger or squarer chocolates will sink at the bottom of the beaker
2. Smaller or finer chocolate floats on the water
3. Good size chocolate rises and falls in the beaker
Sometimes the chocolate that can undulate will also "get stuck" on the surface of the water.
This time rub a little chocolate crumbs into it
Making the water a little cloudy will help the chocolate continue to rise and fall
We can also try to cut more shapes into the chocolate
The trajectory of chocolate will also become rich and interesting
Explanation of the principles
When chocolate is put into soda, the carbon dioxide formed by the decomposition of carbonic acid adheres to the surface of the chocolate, which provides a certain amount of buoyancy. When the buoyancy of the bubble and the chocolate overcomes the gravity of the chocolate, the whole rises; and when the chocolate touches the water, the bubble at the junction of the chocolate and the water escapes, and the buoyancy is not enough to overcome the gravity, and the chocolate sinks again.
Since the amount of bubbles attached to the surface is roughly proportional to the surface area, the specific surface area is too small, and the chocolate cannot float even if the bubbles are completely attached; on the other hand, if the specific surface area is too large, then only the bubbles on the bottom and sides can continue to float when floating to the surface. Only chocolate with a moderate surface area can complete the reciprocation of sinking and floating.
In actual experiments, due to the large surface tension of water, it may appear that the bubbles above the chocolate float to the surface of the water cannot escape due to surface tension. At this time, if you let some grease on the surface of the water weaken the surface tension, you can make the chocolate start to move up and down.
If the chocolate has a special shape, such as a large end and a small end, then only one end of the bubble will escape when it first floats up, then after sinking, because the other end of the bubble is more, it will be flipped under the action of the combined force moment, and the swing movement in the last figure will be generated