I buy a bag of conversation hearts candy for my family every year. I like the look of them in a bowl on the counter and it’s fun to read the cute messages on each one, although I don’t really eat them. My kids kinda like them (definitely not a favorite candy), but they only like certain colors. So we often have lots of extra conversation hearts in 2 or 3 colors that no one wants to eat. This is a great way to use up those extra candies and do a fun Valentine’s Day themed STEAM activity at the same time!
In today’s activity, we tested how well the conversation hearts would dissolve in 6 different clear liquids: hot water, room temperature water, ice water, bubbly water, sprite, and vinegar. Prior to dropping the conversation hearts in each liquid I had my kids predict if the conversation heart would sink or float in each one. So it’s really two activities in one: will it sink or float? (learning about buoyancy), and which liquid will dissolve it best? (learning about polarities and dissolution).
A few years ago we did a similar experiment to this with Peeps for Easter, and later we did it with Candy Corn for Halloween. The Peeps experiment was my most viewed Instagram post ever with over 35k views! Since it seems people like our STEAM activities using seasonal candy, today we are sharing it again with conversation hearts candies for Valentine’s Day! I like holiday candy STEAM activities, because I let my kids have a couple candies each while we do the activity, and then we use up many of them in the activity (which means there are less candies to be eaten by me and the kids).
I shared this activity on my @engineering_emily Instagram account in a reel. It gives a brief overview of the activity in video form. You can view it below:
Conversation Hearts candy in 6 Liquids: Will it Sink or Float and Which liquid will Dissolve it Best?
This is a great Valentine’s Day activity to learn about two STEAM concepts while using up extra conversation heart candies! Kids will enjoy snacking on a few candies as they watch their candies sink or float in each liquid, then watch to see which liquid dissolves the candies the quickest. We tested 6 liquids in this activity, but you are welcome to change it up and use more or fewer types of liquids when you try this at home (you can cut it back to 3 or 4 by cutting out either ice or room temperature water because they had similar results and cutting either sprite or bubbly water because they had similar results). This activity is recommended for children ages 3+.
Materials:
- Conversation heart candies
- 6 small bowls or cups
- Hot water (from tap, not boiled)
- Room temperature water
- Ice water
- Bubbly water (like Topo Chico, Perrier, etc)
- Sprite
- Vinegar
Safety:
This activity involves small candies which pose a choking hazard to children under 3. Older children should be sure to thoroughly chew each candy before swallowing it. Since there are liquids involved, have towels on hand to cleanup spills to prevent sips and falls. Children should not eat any candies that have been soaked in the liquids. Use caution when handling the hot water, and do not use boiling water to prevent burns.
Procedure:
- Fill the six bowls about 2/3 full with the six liquids: hot water, room temp water, cold water, bubbly water, sprite, and vinegar.
- Grab at least 6 conversation heart candies (one per bowl).
- Ask the child to predict if the conversation heart will sink or float in each liquid.
- Ask the child to predict which liquid will dissolve the conversation heart the fastest and the slowest.
- Drop a conversation heart into each liquid and observe what happens.
- Does the conversation heart candy sink or float in each liquid?
- It will FLOAT in bubbly water and Sprite. It will SINK in hot water, room temp water, cold water, and vinegar.
- Which liquid dissolves the conversation heart candy the fastest?
- Hot water dissolved it the best by far, followed by bubbly water and Sprite. We saw little to no dissolution from room temp water, cold water, and vinegar.
- Compare results to the predictions and discuss any differences (see STEAM Concepts Learned section below for more).
STEAM Concepts Learned
Kids are learning about buoyancy when you ask if it will sink or float. The conversation hearts are more dense than the liquid they are dropped into, so they immediately sink to the bottom in all the liquids. However, after a few seconds the conversation hearts in the Sprite and bubbly water eventually floated to the surface and remained floating on the surface of the liquid.
The bubbles (from the carbonation in the bubbly water and Sprite) are attracted to the conversation heart. When they attach to the conversation heart they increase its volume, but don’t increase the mass. Eventually when enough bubbles attach to a the conversation heart, the density of the heart becomes less than the density of the liquid and it rises to the top of the bowl.
Sugar dissolves in water because the polar sugar molecules are attracted to polar water molecules. It dissolves faster in hot water vs room temp or ice water because the hot water molecules are moving faster. The acid in vinegar does not attract and dissolve sugar. The carbonated beverages dissolved the sugar more quickly because the bubbles speed up the water molecules in these liquids (but not as much as hot water).
My kids had so much fun with this activity. They reminded me to check on it every 1/2 hour or so to see if the conversation hearts were dissolving, and we all were excited to see what was happening. I liked how my older two kids (age 10 and 8) were able to understand our discussion about what was happening, why the conversation hearts floated in the carbonated liquids, and why the hot water dissolved the conversation heart the best. My 3 year old enjoyed participating by placing the candies in each liquid and watching to see if the candies would sink or float.
Are you going to try this activity with your kids this Valentine’s Day? Have you tried this activity with Peeps for Easter or Candy Corn for Halloween?
If you liked this activity, you can have it with you (and the Peeps and Candy Corn activities too) anytime anywhere without the ads and photos and extra discussion in the Holiday STEAM Activities for Kids Printable in my Shop.
Holiday STEAM Activities for Kids
The holidays are a perfect time to plan a few fun and festive STEAM activities. This is a collection of 28 holiday themed STEAM experiments and activities. This printable pack includes a table of contents, an introduction with information about Engineering Emily, an explanation of the meaning of STEAM, what to expect in each activity printable, tips for success, and an overview of the holiday activities, followed by 28 two-and three-page easy and fun holiday themed activities for kids.
