Science experiments can be a fun way to keep children entertained at home on the weekends and during school holidays. Erupting volcanos, secret messages with invisible ink, and colourful, gooey slime are just some of the cool experiments you and your budding scientist can try.
Conducting science experiments with your child encourages creativity, and helps to teach important critical thinking and problem solving skillsi. Many DIY science experiments use basic materials you may already have around the house such as vinegar, bottles and jars, adhesive tape, and food colouring, making them an inexpensive way to encourage learning outside the classroom.
Safety should always be your number one priority when trying these, or any science experiments with your child. It is recommended for parents to always be present while the experiments are taking place, even if your child has performed the experiment before. The CSIRO provides a check list of risk factors to be aware of when your child is working on their next big discovery.
Help your child discover how new land is formed by making their own erupting volcano, using a combination of vinegar, baking soda and a few drops of red food colouring . Aside from these ingredients, you'll also need to provideiii:
- A plastic bottle;
- A baking tray;
- Play dough;
- Aluminium foil; and
- Twigs, soil, rocks and/or plastic toys.
First, let your child combine the baking soda and red food colouring in the bottle, then securely fasten the bottom of the bottle to the baking tray with some play dough. Use the foil to create a cone shape around the open bottle and mould the play dough around the foil to form a rough terrain and mountainous shape; next add twigs, rocks and soil to make the volcano look more realistic. Let your child slowly pour the vinegar into the bottle and watch as the lava begins to erupt!
When mixed together, the baking soda and vinegar react to create carbonic acid, which bubbles and fizzes, simulating lava oozing out of the top of a real volcanoii.
Cloud in a jar
If your child has a fascination with the weather, making a cloud in a jar is a good experiment to try. All you need is a glass jar with a lid, approximately 50ml of boiling water, ice cubes and hairspray .
Clouds, which are condensed water or ice, form when warm, moist air cools to the point where it is able to condense around tiny particles in the air. This can be easily recreated on a smaller scale in a few simple steps:
- Pour a small amount of boiling water into a jar and place the lid back on the jar so it rests on top. This will cause the sides to heat-up;
- Place a few ice cubes on top of the lid to begin to cool the air at the top of the jar;
- After a few seconds, remove the ice and lid, quickly spray some hairspray into the jar, and replace the lid with the ice;
- As the warm air in the jar begins to cool, it turns back into a liquid and clings onto the hairspray particles, creating the cloud;
- Let your child remove the lid from the jar and watch as the cloud floats out into the room.
The combination of warm air from the water and cool air from the ice imitate the difference in air temperature in the atmosphere that enables clouds to form.
Invisible ink is easy to make and a fun activity for a kid's party. Sharing invisible messages with friends is a great way to pretend to be secret agents fighting crime or for creating clues to a treasure hunt. All you need to begin writing secret messages is lemon juice and a few common household items, including :
- A spoon;
- A bowl;
- Cotton buds;
- White paper; and
- A heat-producing light bulb.
To make the ink, squeeze the juice from the lemon into the bowl and add a few drops of water to slightly dilute the mixture. Stir the mixture together and your ink is ready to use. Dip a cotton bud into the ink and use it to write a message on the paper. Give the ink a few minutes to dry, and then hold the paper up to the light bulb, being careful not to let the paper touch the blub, and watch as your message is revealedv!
The lemon juice oxidizes and turns brown as it is heated, making the ink visible. Adding in the water ensures that the ink is completely unnoticeable until it is heated over the light bulbv.
Static electricity is what causes your hair to stand on end and those little zaps you sometimes feel when you touch an object in dry weather. This experiment is a fun and safe way for your child to see the basic principles of the attraction between positively and negatively charged particles in action. To begin the experiment, you will need the following itemsvi:
- Two inflated balloons;
- An empty aluminium can;
- Woollen fabric; and
- Hair, of course!
There are three variations to this experiment that demonstrate the interaction between positive and negative charges. First, rub each of the balloons against the woollen fabric and then try pushing the balloons together to see if they cling or repel each other. Second, rub one of the balloons against your child's hair and take a look in the mirror as you pull the balloon away; what happens to their hair? For the third experiment, rub the balloon against your child's hair again and then place the aluminium can on its side on a flat surface. Hold the balloon near the aluminium can and watch as the can begins to roll towards the balloonvi.
Friction between the balloon and the fabric, or the balloon and hair causes negatively charged electrons to jump to the balloon, which creates static electricity. Since your hair and the can both have positive charges, they will be attracted to the balloon, but the two balloons won't attract each other as they both have a negative chargevi.
Gooey cornflour slime
This experiment might be more appropriate for older children, who already have an understanding that fluid substances will take the shape of whatever container they are in, while solid matter will hold its shape. Making cornflour slime can help your child understand how special types of fluid that don't follow traditional rules behave. To make your gooey slime you will needvii:
- Food colouring;
- A small mixing bowl;
- A plastic spoon; and
Quantities of each ingredient will depend on how much slime you'd like to make and can easily be judged by eye as you mix them together. Pour as much of the cornflour as you would like into the bowl and slowly begin to stir in the water, a little bit at a time, until the cornflour becomes a thick paste. Then, add a few drops of food colouring to the mixture, and once the gooey slime has the desired colour, you can begin to experimentvii.
Have your child stir the slime very slowly and then quickly to see if there is a difference in how difficult or easy it is to mix. At a slower speed, the slime should be relatively easy to stir, but at a faster speed it should be nearly impossible. Slime is a sheer-thickening fluid, which means that as pressure is applied, the viscosity (or resistance to force) of the slime increases and it begins to behave more like a solid. Ask your child why they think this is happening to see what they think the reasons are. Scientists don't fully understand how this happens, so maybe your little scientist will be the first to discover the secret one dayvii!
Some of these concepts might take a little creative explanation when you are recreating them with your child. These experiments can be a great way for you both to discover scientific principles in action.