Our Science columnist, Dr Naomi Lavelle, has some summer fun with her son Rohan and shares some ideas to keep the kids entertained (and educated)
Yay for summer holidays! It’s great to take a break from the school rush, the homework and the packed lunches and everyone is a little more chilled. But after the initial feeling of freedom can come a bit of reality; children like to be entertained, a lot. It can be hard to come up with activities that don’t involve screens and don’t cost much. Science just may have the solution.
Here are three science experiments that your children can try at home. You probably have everything you need for them already. As an extra bonus these experiments have a reduce, reuse, recycle message to them as they can all be done with the same small, plastic bottle.
Entertainment, environment and education, the summer holidays look a lot brighter with a little science.
The Sneezing Alien Experiment
You will need:
A small plastic bottle craft material to decorate your alien (optional),
a jug of water small measuring jug washing up liquid food colouring (optional),
white distilled vinegar,
bread-soda (also called baking soda or bicarbonate of soda… but NOT baking powder)
a small funnel or rolled up piece of paper and
a deep tray or bowl.
Safety tip: The ingredients used for this experiment are all safe and commonly used around the kitchen. However, any splash of vinegar to the eyes will sting so best to wear protective eyewear and, if you do get a splash to the eyes, rinse with cool water.
What to do:
1. First decorate your bottle to look like an alien. You can use markers or stick on craft material and just let your imagination take over… three eyes, five arms, feathers, whatever you like.
2. Once you have decorated the bottle fill it one-third full with water and place it on the tray or in a bowl.
3. Add a few drops of food colouring (optional).
4. Add a squirt of washing up liquid.
5. Next add a heaped teaspoon of bread-soda and give it all a good mix or gently swirl the bottle to mix all the ingredients together.
6. Time for the fun bit… measure out about 40mls of vinegar into your small jug and 3,2,1… go! Add all the vinegar quickly to the bottle.
7. Watch as your alien erupts with a big, bubbly sneeze; and when it is finished you can do it all again by adding another spoon of bread-soda and some more vinegar.
The science bit: This fun experiment is all about chemistry and things called acids and bases (also called alkali). When you mix an acid with a base you get a chemical reaction and a gas is usually released; the vinegar was the acid and the bread-soda was the base. When you mixed the two together they reacted and gave off a gas called carbon dioxide. The gas got trapped in the washing up liquid, creating all the fun, foamy bubbles.
Magic Rice in a Bottle
You will need:
A small plastic bottle;
a packet of uncooked rice;
a funnel or rolled up piece of paper.
What to do:
This is a quick and simple experiment that is bound to impress your friends and family.
1. Ensure that the bottle is clean and dry and then fill it with uncooked rice. You can use a funnel or a rolled-up piece of paper to make this easier.
2. Tap the bottle on a hard surface a few times to make sure the rice is tightly packed and then top up with more rice as necessary.
3. Push the pencil (point side down) slowly into the bottle of rice until only about one-quarter of the pencil is sticking out of the top.
4. Lift the pencil up and down a few times (don’t remove it fully from the rice), you are doing this to pack the rice around the pencil in the bottle.
5. Now for the fun bit… hold the top of the pencil and lift, you should find that the whole bottle comes up with the pencil (if this doesn’t work first time, just tap the bottle a few more times and lift the pencil up and down – it takes a little knack to get it right).
The science bit: This experiment uses the force of friction to lift the bottle. A few grains of rice rubbing against the pencil will not create enough friction force to hold the pencil tight enough to lift the bottle, but when the bottle is full, the small friction forces between each grain of rice add up to enough friction to tightly hold the pencil in place.
Bottle Top Hovercraft
You will need:
A pop-up top off a small plastic bottle.
An old CD.
Safety tip: You need to use strong glue for this experiment so this step should be carried out by an adult as the glue bonds very quickly and tightly.
What to do:
For this experiment you just need the top off your bottle, it needs to be one that you pop up to open and push down to close.
1. Firstly, place the bottle top directly over the hole in the centre of the old CD, once you are happy with the position then add some strong glue to the base of the bottle top and stick it into place over the hole of the CD (you will need to get an adult to do the glueing for you).
2. Wait a few minutes for the glue to set.
3. Once the glue has set place the bottle top into the closed position.
4. Blow up the balloon but don’t tie it. Place the neck of the balloon over the bottle top.
Tip: to prevent the balloon from deflating as you do this, you can twist the neck of the balloon.
5. Place the CD on a smooth flat surface.
6. When ready, pull up the bottle top into the open position and watch as the CD takes off along the surface like a hovercraft. Once the balloon has deflated the hovercraft will stop.
The science bit: The air from the balloon escapes through the cap of the bottle and creates a cushion of air between the CD and the surface. The CD is light enough that this cushion of air can lift the CD off the surface slightly, reducing the friction between the CD and the surface and the moving air propels the mini hovercraft around until all the air is gone and it’s time to blow up the balloon again and repeat.