Holiday Science Experiment: Sink or Float?
The goal of today's science experiment is to discuss the idea of density & buoyancy (which are physics concepts) and also to help kids understand the concept of making predictions.
This science activity is always a BIG hit with kids (water ... splashing ... :) but many times they will just drop everything in the water without really thinking through the idea of PREDICTING what will happen to the item -- will it sink or will it float?
If you'd like to read a few books about the concept, we recommend the following books that share more details about density and buoyancy (the affiliate links will give you details about each one):
And no, we didn't find any holiday-themed sink & float books -- may be time to write one!
Here are some common items you will have around the house during the holidays -- perfect for a holiday science experiment:
• oranges (if you have 2 sizes, that's even better!)
• fresh cranberries
• holiday bows/ribbon
• whole nuts
• flower petals (like from a poinsettia)
• small branches from a live christmas tree
• candy canes (wrapped & unwrapped)
• light bulb covers (we pulled some off of our no-longer-working outdoor light string)
• ornaments (plastic or glass work best)
You'll also need a large bowl or container of water. I like to use a clear plastic or glass container so it's easy to see the items from a side view -- gives the kids a good idea that many items may sink before they pop up and float or might begin to float but will eventually sink.
Gather all your items on a tray or basket and talk to the kids about which they think will sink when dropped in the water and which will float.
The kids can list each item in the left hand column and then circle their prediction. Once they drop the items into the water, they can circle their results.
For example, my daughter picked up both oranges and said the smaller one would float while the larger one would sink because it felt heavier & more dense (older kids may already know the idea of density from school science classes but putting it to use is a whole other thing!)
What happened? Both oranges floated!
Then we used both a plastic holiday bow and a cloth holiday ribbon (this is why holiday science experiments are so fun ;) -- the cloth ribbon floated for a while but once it became saturated, it sank to the bottom. However, the plastic bow remained floating. A great discussion about what the make up of each item ensues.
The biggest surprise for us was the light bulb cover -- we really thought it would float for a while and then sink once it filled with water but it only filled partway with water (there was an air bubble that formed at the tip) so it continued to float!
What IF things were cut open????
The prediction was that if we cut open a cranberry, it would "lose the air inside and be more dense so it would sink">
Well, let's see ....
Interesting -- (I actually thought the water might fill the pockets and have it sink but the flesh must not be very dense in fresh cranberries).
Try that with other items -- will a peeled orange float or sink?
How about the candy cane? We put in one that was wrapped & one that was unwrapped (I'll keep the results a secret on that one ;)
If you try this holiday science experiment over winter break, leave us a note in the comments or on our Facebook page & let us know what items you used!
Looking for more STEM ideas?
The STEM Toys & Game Store showcases all the latest & greatest in learning toys for kids so be sure to check out the selection! It's a great place to find holiday gift ideas too.
Original article and pictures take http://www.kcedventures.com/blog/holiday-science-experiment-for-kids site