It might be the holiday of love, but as a teacher, you dread it. With all of the sweets and treats, Valentine’s Day is up there with Halloween when it comes to the chaos it can cause in your classroom. I struggled as a new teacher to keep my students engaged at all on Valentine’s Day. All they had on their mind were cards and candy. That is until I figured out that science could be my cupid’s arrow. And so, these engaging hands-on Valentine’s Day science experiments were born!

It can be hard to keep upper elementary students engaged on a regular day. Throw in a holiday like Valentine’s Day, and it gets even more difficult. Instead of fighting the holiday, embrace it! Use the theme to your advantage and have fun with Valentine’s Day science experiments! Here’s how I use them in my classroom.
Valentine’s Day Science Experiments Set Up
When figuring out how to use Valentine’s Day science experiments in my classroom, I knew that I wanted to make sure my students were engaged in the content as long as possible before that party took place! Reducing downtime helped save my sanity, and it helped the day pass more quickly for my students as well.
That is why I always set up my Valentine’s experiments as rotating stations! I set up each experiment around the room so that students get a chance to try multiple experiments during the day.
At each station, there is a sign with the name of the experiment, the directions, any supporting worksheets the students might need, and the materials.
Then, I break the class into groups of 4-5 students. Sometimes I have enough students so that each station is being used at once and sometimes one station goes unused for a rotation.
If you are worried about having enough space for each station, you can create larger groups or decrease the number of stations you use. The key is to find that sweet spot that works for your class. And . . . it might be different from year to year.
keep things moving!
By this time in the year, my students are very familiar with the expectations and procedures for science investigations and experiments. However, before beginning, I always review the expectations with my students. This really helps to keep those procedures and expectations front of mind.
In my classroom we break our science experiments into 3 segments:
- Explore materials (approximately 3-5 minutes)
- Conduct the experiment / complete the activity (time varies by activity)
- Clean up and re-set for the next group (about 3 minutes)
To determine the final amount of time for each rotation I must first determine the time needed for each activity. I complete the activity myself first in order to determine this. If I have an activity that takes less time than the others I may add in a reflection component or a second activity. By keeping the time for each activity really close, it keeps all the students engaged during each rotation.
Once the expectations have been set, the learning gets underway. I circulate around the room helping students with any issues and observing the fun!
my favorite valentine’s day science Experiments
Let’s jump into the fun stuff: the experiments! There are 8 experiments I absolutely love using for Valentine’s Day.
I’ve found that this combo of experiments has a little something for all of my students, so off-task behavior is always at a minimum. However, you could use any of these experiments as a whole group activity, and it would still be just as fun!
These activities include hands-on experiments where students test their theories, STEM activities, and investigations where students get to create fun take-home items while practicing science skills.
Do one, five, or complete all eight. With so many options you can really create the perfect Valentine’s Day science activity that fits your classroom perfectly.
Valentine’s Day Science Experiments that break hearts
When you hear Valentine’s Day, what is the first word that comes to mind? Hearts, right!? That’s why I’ve taken advantage of all the hearts I can in these hands-on experiments!
Disappearing Hearts
Candy hearts are no longer just for munching! In this experiment, students test different liquids to see which one will make the heart disappear the fastest. I particularly love this science activity because the materials are flexible! I can easily grab whatever is in my fridge or available in the teacher’s lounge to use for liquids.
Students use four different liquids (including water as a control) and add a candy heart to each at the same time (This is when having at least 4 students in a group is helpful!). They time the process and take observational data at each specific timed interval.
You’ll love hearing the conversations this experiment sparks as each student watches a cup and reports on what they see. Some of my favorites are:
“Look, look, look! Something’s happening!”
OR
“Where did it go!?”
You can really tell the students are invested in this one!
Dissolving Hearts
When I first tested out Valentine’s Day science experiments with my class, the kids loved the Disappearing Hearts activity so much, that I knew there was more that I could do with candy hearts and still keep them engaged.

That’s why I added a Dissolving Hearts experiment to the rotation.
In this experiment, students use hot, room temperature, and cold water to test which dissolves the hearts the fastest.
Students can simply turn on the hot water tap in the bathroom, let it run a little, and fill their cups. The water DOES NOT need to be boiling, just warmer than room temperature.
Students make their predictions and then drop in their hearts. Honestly, this has been one of the most engaging ways I’ve found to reinforce the concept of solubility!
Crystal Hearts
While the first two activities are all about making hearts disappear, this experiment is all about growing a heart! Your students will be amazed to see a heart grow right before their eyes.
You will need:

- Pipe cleaners
- Popsicle sticks
- String
- Large jug or jar
- Boiling water (see my note below for safety!)
- Borax
- Measuring cups and spoons
If you have ever grown a crystal snowflake, this experiment follows those same principles. Simply have students create a heart shape with the pipe cleaner (you can even do this ahead of time for ease of transitions!) and attach it to a popsicle stick with some string. Lower it into the Borax and water mixture and watch the heart start to grow.
This experiment does take time. 12-24 hours to be exact. So, while at this station, I have students observe the solution and predict what they think will happen and why. If you teach the states of matter, this experiment is a must!
Note: This experiment does require close adult supervision as students must use boiling water to create their crystals. I usually station myself here at the beginning of each rotation to take care of the water and then circulate around the room.
We Heart STEM
Building and creating are sure-fire ways to keep students engaged during the Valentine’s Day chaos. So, of course, these next two heart activities always make my rotation!
Heart Catapults and towers
In each of these activities, students are challenged to take on a building task. For each, the group is given a set of materials to use and the object that needs to be created. The rest is up to them!
You can be flexible with the materials you provide students making these easy challenges to prep. Common items like popsicle sticks, paper, tape, or even items from the recycle bin are perfect.
Students must brainstorm a plan, build their structure, and then revise if needed.
Candy Heart Catapult
In one activity, students create Heart Catapults. Enter those candy hearts again! The team must make a catapult that shoots the candy heart. Their goal: get their heart to go farther than the other teams!
Adding in a little competition always gets the creativity flowing. I mark out distances with painter’s tape in the hallway in front of my room so that teams can test their creations. They are only able to test their creation 2 times before their final distance is recorded. So, they take their building and revisions seriously!
If you don’t have time to include all 8 activities at one time, this activity makes a great one to do on its own. The entire class can work on building and testing at the same time. Then move everyone to the hallway, gym, or even outside for the final test!
Heart Towers
In the second activity, students create Heart Towers. Their mission is to have the tallest tower in the class built out of the given materials.
In this Valentine’s Day STEM activity, I challenge them by only allowing one revision! I find that this helps slow down the planning phase and students are more intentional about what they build.
For this activity, you can provide any type of building materials that you have on hand. My favorite building materials include heart-shaped marshmallows and toothpicks.
Valentine’s Day Science experiments that will make their hearts burst!
Okay, not literally, but your students will definitely light up as they complete these fun, and perhaps a little messy, Valentine’s Day science experiments!
Sparkly Explosion
Take the baking soda and vinegar volcano to the next level with this Sparkly Explosion experiment.
You will need:
- Tall container
- Baking soda
- Vinegar
- Red food coloring
- Glitter
- Pan (for the mess)
- Measuring cups and spoons
Students work on following the recipe to create the explosion. Since the basic baking soda and vinegar “explosion” is one students are often familiar with, I love taking it to the next level by trying to add different materials to the vinegar and baking soda to see what happens! This allows them to use their prior knowledge to make a hypothesis and then test it out.
Some materials students have tried include water, glue, candy hearts, and hand sanitizer. The possibilities are endless! Let them be creative using any available supplies. It’s a win for Valentine’s Day!
Secret Messages
I love having students do this experiment right before our Valentine’s party because they can make their own Valentine’s with secret messages to give to each other!
You will need:
- White paper
- Baking soda
- Water
- Paint brush
- Spray bottle
- Bowl
- Fruit juice (I suggest lemon as it works the best!)
Students mix the water and baking soda together and use the paintbrush to write their message. Once it dries, they spray with lemon juice to reveal what they wrote!
They all feel like secret agents on a mission, and dare I say may even forget about all that candy waiting for them. I love that they get to practice reading and following directions independently!
Valentine’s Day Slime
This is the crowd favorite! Slime is all the rage right now, and this Valentine’s Day Slime does not disappoint.
You will need:
- Water
- Glue
- Liquid starch
- Red food coloring
- Bowl for mixing
- Measuring cups
- Baggies
Students add the glue, water, and food coloring to a bowl and then stir while adding in the liquid starch to make their Valentine’s Day concoction.
Most kids love getting a little dirty when creating some slimy fun, so I would suggest having a package of wet wipes handy if there isn’t a bathroom nearby.
The best part of this experiment is that students get to take their slime home for even more fun!
Make Valentine’s Day Science Experiments even easier
Valentine’s Day can be quite a sugar rush! So, having a solid plan to keep your students engaged is a must. Keep them learning and engaged with a fun day of Valentine’s Day science. I’ve pulled together all of my favorite Valentine’s Day science experiments for you in this Valentine’s Day Science Stations resource! It is sure to make Valentine’s Day a day you look forward to instead of dread.
Looking for more Engaging Science Fun?
Could you use more engaging and hands-on science activities?
- Fun Activities for Teaching States of Matter
- Hands on Weather Activities
- Winter Science Activities for Upper Elementary
save these valentine’s day science experiments
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