3 Hot Experiments for the Summer!
July is just the time for fun outdoor activities! Check out some cool experiments below that teaches and demonstrates the scientific theories of heat transfer and changes of state! We hope you have fun trying out these from the comfort of your home.
1. Slushie Transformation
This activity is a super fun one for a hot day! Just take note to start early in the morning so that you and your child will have refreshing drinks to cool off during lunch! All you will need are:
- Juice (of your choice)
- Ice (lots of it)
- A large bowl
- A basin
- A non-contact thermometer
Start off by filling the large bowl with as much juice as you’d like to make into a slushie. Next, place the bowl containing the juice into the basin, and surround the bowl with a liberal amount of ice. Make sure that at least 3/4 surface area of the bowl is surrounded in ice for the experiment to work. Cover the ice with salt, and let it sit. Be careful not to get any salt into the juice!
This experiment takes a while before results start to show. At the 30 minute mark, take the temperature of the juice. Observe how the ice has changed its state due to the salt. Give the juice its first stir at this point, and ensure to continue stirring it every 30 minutes so that the juice does not turn completely to ice. You can also encourage your child to take note of the change in state of the juice to slushie form!
The simple science behind this experiment shows the change of state when temperature is lowered – i.e. how a liquid turns to solid state. It also demonstrates the process of heat transfer, and how salt, as a chemical, lowers the temperature of ice due to an endothermic reaction when it comes into contact with the ice.
2. Invisible Heat Crush
How cool would it be to crush a plastic bottle without even touching it? You will need just a few simple items to leave your child mesmerized by this experiment! They are:
- Some boiling water
- An empty disposable plastic bottle
- Crushed ice (lots of it!)
- A basin
- Mittens or a basin to protect your hands from heat
To start, prepare a basin and fill it with crushed ice. Next, boil some water. Make sure that the water is boiling hot before pouring it into the plastic bottle. Caution: Adults should handle this step to ensure safety. Screw on the bottle cap, and use the mittens or a tea towel to carry the bottle over to the basin. Place the bottle into the basin, and make sure that the bottle is surrounded with the crushed ice. Wait for a few seconds. Closely observe the bottle to see if there are any changes to its size!
Due to the process of heat transfer, the hot water in the bottle was cooled rapidly when placed into the basin filled with ice. Due to heat energy, steam molecules in the bottle move around more rapidly when the boiled water was first placed in the bottle. However, as the temperature of the contents in the bottle were lowered rapidly when placed into the ice, there was a loss of heat energy, causing the steam molecules to lose heat energy and turn into water instead. This caused a contraction since less space in the bottle was taken up with the molecules being less active. As such, a negative pressure was created, causing the bottle to contract in size!
3. Rising Water Levels
This experiment is another interesting one that moves water without needing to touch it! All you will need is:
- A flat plate or tray
- A candle
- Food Colouring (optional)
- A large transparent glass jar
- A non-contact thermometer
Start by filling the shallow bowl or dish with some water. Add in a few drops of food colouring of your choice and mix well. The food colouring is not necessary, but makes it easier to observe the effects of the experiment. Next, light the candle and place it in the middle of the water-filled tray. At this stage, nothing happens. Now, cover the candle with the glass jar, and closely observe what happens.
The water level in the dish starts to lower, and is ‘sucked’ into the glass jar! Watch as the water level in the jar keeps rising. After a while, the candle will be extinguished. Why is this so? First, the lack of oxygen in the glass jar caused the candle to eventually be extinguished. While this happens, this causes the temperature within the glass jar to fall at the same time. The fall in temperature caused a vacuum to form in the jar – this in turn ‘sucked’ the water in! Repeat the experiment once more, and this time, constantly take the temperature of the air within the glass jar to spot the trend!
We hope you and your child enjoy these educational activities! Should you and your child be interested in science and scientific endeavors, check our our YMCA Learning Centre STEM programme! This programme aims to spark an interest in students in learning how the world around us works, through experiential learning. Do contact us to find out more!