Science Fun!

Today we carried out a science equipment. The question posed was - 'what will happen when we add raisins to a glass of fizzy?'. We brainstormed our ideas - some ideas were:

• the raisin will float because it's very light
• the raisin will turn back into a grape because it will absorb the liquid
• the raisin will dissolve because of the sugars in the liquid and the sugars in the raisin
• the raisin will lose its colour because of the sugars in the liquid

Then we gave it a go - this is what happened...

We were amazed by the dancing raisins! We think that the raisins kept rising and falling because of the bubbles. The bubbles were attracted to the raisin at the bottom which made it light enough to rise to the top, then the bubbles popped which made the raisin heavier again so it sank. We shared lots of ideas about why this all happened, linking to the gas in the fizzy, the dehydrated fruit and the density of it. 

We wondered if we could prove that it was all related to the gas in the fizzy. We tried the same experiment with water and it didn't have the same effect - nothing happened. Then we tried adding lots of raisins to a glass of fizzy - we wondered if there wouldn't be enough bubbles to make them all float. We found that the raisins still floated up and down. 

We still had questions and wonderings - we wonder...

• does this experiment work with different types of fizzy? Like L&P or Coke?
• does this experiment work with different types of dehydrated fruit?
• what if we used sparkling water instead of the fizzy? does the sugar content of fizzy have an effect on the experiment?

We are going to try these ideas next week!