What melts ice the fastest? 3 STEM activities for kids

Which materials make ice cubes melt the fastest? Do some colors absorb more heat than others? And, can you stop ice from melting? This post explores these three questions using simple science experiments for kids!

There are three experiments we’re going to cover. Click the title of each to jump right to the steps if you’d like! The first science experiment is detailed in this post. For 2 and 3, I briefely cover them here. Check out their individual posts for more photos and deeper explanations!

  1. Which materials melt ice the quickest?
    • Teach your children how different substances can provide insulating properties or make ice melt faster. This simple science project explores how you can influence the melting rate of ice with household materials.
  2. Which color absorbs the most heat?
    • Test the theory that some colors absorb more heat than others using direct sunlight to melt ice.
  3. Can you stop ice from melting? Or at least slow the melting process down?
    • Take your children’s learning even farther by seeing if you can prevent ice from melting!

Before you start: Download these worksheets!

While these activities are great on their own, you may want to use worksheets as a form of assessment. If so, either head to my Teachers Pay Teachers store to download my Free Don’t melt the ice! STEM challenge and worksheet bundleor download the individual worksheet for this experiment as a PDF below.

I also have a Scientific method worksheet available for free in my shop.

Experiment 1: Exploring freezing point depression

Why do some materials melt ice faster than others?

And, why does road salt melt winter ice off of the driveway, even when it’s still -25 outside? To answer this, I consulted Brittanica’s article Why does salt melt ice? Essentially, when the ionic compound of salt is added to ice, it lowers the freezing point of water via freezing point depression. If you want to read more of the scientific theory behind this, I’d suggest checking out their article.

But, not all cities use salt to melt the ice on our roads – Some put sand down! This got me wondering… What else could we use from the cupboard to melt ice? That brings us to our first experiment on what makes ice melt.

How to create the experiment

So, how can we use the science above for a kid-friendly experiment? Well, we can test household ingredients and their ability to melt ice by placing ice cubes of the same size in containers and then adding other substances on top. If the substance melts the ice faster than the ‘control’ cube (an ice cube with no added substance), then it lowers the freezing point depression. If the added substance slows down the melting process, it insulates the ice cube.

To keep this exciting for the littles, I’d highly suggest letting them choose the objects to test. Since we know salt is used to melt ice quickly, I’d also emphasize using a salt spread as one of your test objects since it makes ice melt fastest. Other than that – See what’s in your cupboard!

Materials

  • 1 container for each test material
  • 1 ice cube for each test material and one extra for the control
  • Salt(whatever you have on hand – rock salt, table salt, etc)
  • Numerous materials to test (sand, dirt, rocks, flour, salt, oatmeal… Whatever you have on hand!)
  • We used 3 teaspoons each of salt, baking powder, coffee, and brown sugar.
Make sure you evenly cover each cube

Instructions

  1. Place the ice cubes in separate containers (or muffin tin)
    • Make sure you leave one ice cube with no substances – This is your control! I used two to be safe.
  2. Gather your test materials, making sure that you have equal amounts of each. Three teaspons is a good amount
  3. Take note of the time before you start
  4. Let the containers or tray sit and observe what’s happening
    • See which substance melted the ice fastest and which took the longest. Be sure to wait until the solid ice is completely melted
  5. Communicate the results! (see ours below!)

Questions to prompt deeper learning

Here are some questions to ponder together after the experiment has finished:

  • Which material melts ice faster? Why do you think that is?
  • How come salt melts ice?
  • What does this science experiment teach us? (For older kids, ask what does this experiment teach us about melting points?
  • How can we use what we learned in everyday life? (Do we ever need to make ice melt?)

Encourage your students to share their observations by asking open-ended questions like “What did you notice?” or “What do you think was happening?”

Here’s what happened when we tried it…

The ice in the salt container started melting right away. It only took 5 minutes and 30 seconds! The control cubes melted two minutes after. Next to melt was the ice cube in the brown sugar container, then the coffee, and the last to melt was the ice cube in the baking powder. The cube in the baking powder took 35 minutes to melt!

I was pretty surprised at how well the baking powder insulated the ice cube! Check out our results below.

This is at the beginning.
Within a few minutes the control ice cubes and the ones in the salt and brown sugar started melting.
By the time the salt cube was almost entirely melted, the baking powder cube had just started to melt.

And the winner is…

Salt!

Did you try this experiment? We would love to hear the results!


Experiment 2: Demonstrating heat absorption by color

ice melting on colored paper

Do certain colors absorb more heat than others?

Different colors do absorb heat differently. The Kidadle team explains the science behind this quite thoroughly, so I’d suggest you check out their article if you want a more in-depth explanation. But, I’ll sum it up here:

The heat energy from the sun’s rays is reflected, absorbed, or passes through objects. The darker a color, the more the heat will be absorbed. The lighter the color, the more the thermal energy can transmit through the object. This means that darker colors will be hotter and lighter colors will be cooler if exposed to the same heat energy.

Test this theory by creating the experiment below!

How to create the experiment

Materials

  • 7 ice cubes
  • 7 different colored sheets of paper, including white and black
    • If you don’t have 8, that’s okay! Just use the colors you have on hand… That’s what I did and that’s why I don’t have the true rainbow of colors!
    • Half of a regular-sized construction paper is good
  • A hot day with some direct sunlight

Instructions

  1. Place one ice cube on each piece of paper
  2. Record your starting time
  3. Let the sun melt the ice
    • Check on your ice every few minutes – Track which order they melt in!
  4. Observe and communicate your results – What did you see?

Head over to my post, which color absorbs the most heat, to see what happened when we tried this experiment. I also share a freebie worksheet I’ve created just for this experiment, too!

Experiment 3: Slowing the melting process of ice

This experiment is fun to do in the wintertime, but you could do it anytime. By using simple household materials, you can challenge your children or students to design their own ice insulators. The real challenge? Seeing if they can keep an ice cube from melting!

Heat energy

The three experiments in this post deal with heat energy. Heat energy can be transferred via conduction (when two objects are touching), convection (molecules moving), or radiation (electromagnetic waves).

Simscale has a super detailed post on heat energy here, if you’d like a deeper explanation.

If we want to prevent heat energy loss, then we need to insulate our object!

How to create the experiment

As long as there is a control (an ice cube with no insulator), the way this experiment is designed is totally up to the children! Check out the suggested materials below for prompt ideas.

Materials

  • Enough ice cubes to have one in each container
  • A sealable container for each ice cube
  • Any materials required for the child’s insulator design
    • Ideas: Wood shavings, cotton balls, bubble wrap, towels, pom poms, rice… Whatever is on hand!

Instructions

  1. Brainstorm: Which items would make good insulators?
  2. Design: Design an insulator
  3. Test!
    • Create a control model by placing an ice cube in a container with nothing in it
  4. Put one ice cube in each of the other containers you are testing
  5. Note the start time
  6. See whose ice cube takes the longest to melt!
  7. Communicate the results

Head over to my post, Ice insulation: STEM challenge, to see what happened when we tried this experiment. I also share a freebie worksheet I’ve created just for this experiment, too!

Did you try any of these experiments? We would love to hear how it went!

Elke Crosson
Elke Crosson

Elke Crosson has her BA in International Relations with a minor in Spanish at UBC (Okanagan). She is currently in her second year of the Master of Teaching program at the University of Toronto, with dreams of becoming an elementary-level teacher.