Ice, snow, frost, and fog… winter weather can bring us many opportunities to look at different states of matter using one substance: WATER! Kids love hands-on experimenting and we’ve chosen three fabulously fun experiments to engage with water as a liquid, a solid, and a gas!
Grab your supplies… here we go!
Liquid: Surface Tension
Supplies:
- Small clear cup
- Bowl or plate for under cup
- Dropper or spoon
- Water
Experiment:
- Fill the small clear cup with water until it is full.
- Keep adding water a little at a time and observe how far you can “fill” the cup.
But Why!?
Water molecules form bonds between each other causing surface tension. This bond allows water molecules to hold on to each other even when the water is above the rim of the cup. The water molecules will continue to hold strong until the force of gravity is greater than that attraction of the water molecules to one another.
Solid: Ice Balls
Supplies:
- Frozen water balloons – ice balls – as many as you choose to experiment with
- Food coloring – optional
- Various different melting materials (ie. salt, flour, sand, sugar, etc)
- Bowls to hold the different ice balls
- Spoons
Experiment:
- Create ice balls by filling balloons (or other containers) with water, adding food coloring if desired, and freezing them.
- Put each ice ball into a separate bowl and add your melting material using the spoon.
- For it to be a fair test, use a measuring cup or spoon so you add the same amount of each melting material to each bowl with an ice ball.
- Observe to see which melting material works best, which melts the ice the fastest.
But Why!?
Adding any other substances to water lowers the temperature at which the water freezes. So, instead of water being ice at 32 degrees, when we add salt to the water, it will not turn to ice until it is 15 degrees. The freezing point varies based on the material. We use salt on our roads because it lowers the freezing point of water requiring it to be a lot colder before the ice forms. Any substance that dissolves in water disrupts the freezing process of water causing it to have to be colder before it turns into ice.
Gas: Fog in a bottle
Supplies:
- Clear plastic bottle
- Cork – that fits the bottle top
- Rubbing alcohol
- Bicycle pump – with basketball pin
Experiment:
- Cut the cork enough so that the bicycle pump pin will fit into the cork with the end sticking out allowing the air to be pushed into the bottle.
- Push a hole in the cork allowing the bicycle pump pin to fit with the end sticking out of the bottom of the cork into the bottle.
- Pour a little bit of rubbing alcohol into the bottle – enough to coat the inside of the bottle.
- Fit the cork in the top of the bottle
- Pump air into the bottle with the bicycle pump
- Pull out the cork when the pressure has built up in the bottle.
But Why!?
Fog is made by lots of tiny droplets of water. It is formed by condensation in the air. Condensation is when water molecules in the air come together with other water molecules in the air forming droplets of water. When the water vapor in the air combines with the other water vapor in the air, we see fog. When there is a lot of pressure in the bottle, the molecules get compressed, but as soon as the pressure is released the molecules (in this case from the alcohol) quickly grab onto other molecules forming the fog!