Find yourself with a bit more free time these days? Want to learn some new things ... but from the comfort of your own home? We've got you. We’ve compiled some fun science experiments you can do with stuff you’ve got around the house, plus the science behind each of these results.
When you can’t go to science class, bring science class to you!
But remember: This is a time to be practicing social distancing or, if you’ve been exposed to COVID-19, self-quarantining. If you don’t already have the items you need to do one of these experiments, don’t put yourself or others in danger to get them!
Write a Message in Invisible Ink
What You Want to Learn: Is is possible to write a secret message?
Things You'll Need
- Juice from one lemon
- Bowl or container
- Paper (white printer paper works best)
- Q-tip or small paintbrush
- Heat source (a flame from a lighter or candle works best, but if you don’t have adult supervision, you can also use a bright lightbulb that gets really hot)
What You Do:
- Squeeze the juice of the lemon into the bowl. You can add a few drops of water if you need a little more liquid.
- Dip the Q-tip or paintbrush into the lemon juice, and use it to write a message on the piece of paper. The writing won’t show up right away, besides turning the paper a little damp.
- Allow the secret message to dry, and then hold the paper over the flame from a lighter or a candle. Go carefully to avoid letting the paper catch on fire.
- You should start to see that the lemon juice will start to turn brown, revealing the contents of the message.
- Voila! You made invisible ink. You can use this method to pass secret messages between your siblings or anyone else you’re stuck inside with! To really throw people off the trail, you can write decoy messages with a pen or pencil on the paper as well. To anyone else, it could look like just an ordinary paper with a few notes you wrote to yourself. But only the recipient will know that they need a candle to reveal its true contents ...
Why It Works:
This invisible ink method works because of the power of oxidation. Oxidation happens when the sugars of the lemon juice start to decompose and get released into the air. One of the things that happens during that process is the sugars start to turn brown. The reaction becomes even more pronounced as the fibers of heavy paper create more sugars when combined with acidic lemon juice, which also causes a browning process.
Oil and Ice Experiment
What You Want to Learn: Do oil and ice really hate each other?
Things You'll Need
- Vegetable oil or olive oil
- Baby oil
- A tall cup
- 1 ice cube
- food coloring (optional)
What You Do:
- Pour the vegetable or olive oil into a cup, filling it a little less than halfway.
- Gently pour the baby oil on top, not quite filling the cup.
- Very carefully put an ice cube into the water. Do you notice that it reacts differently than when you put ice cubes into a cup of water or soda? You should see that the ice cube seems to float between the two oils. As it melts, you can see the way it floats up and down the cup, as well as how the droplets of water from the melting ice cube interact with the oils.
- If you want, you can put a drop or two of food coloring into the cup to observe how it interacts with the different oils.
- You just made a floating ice cube!
Why It Works:
This is all about density. Ice is less dense than water and oil, so it floats on top of it.
Make a Glowing Bouncy Egg
What You Want to Learn: Can I make an egg glow and bounce?
Things You'll Need
- 1 egg
- 1 yellow highlighter
- vinegar
- jar big enough to hold an egg and liquid
- blacklight
What You Do:
- Remove the tube of highlighter ink from the plastic highlighter. Place it in a jar with vinegar, and use your hands to squeeze the highlighter ink into the vinegar. Remove the plastic tube once you’ve squeezed the color into the vinegar.
- Put a raw egg in the highlighted vinegar, and then pour more vinegar on top to make sure the egg is completely covered in vinegar.
- Now, you wait. Put the jar somewhere it won’t be disturbed, and wait for at least two days, or up to a week.
- After at least 2 days, check on the egg. If it looks like the shell has been completely dissolved in the vinegar, rinse it under warm water to remove any residue.
- Try to give it a little bounce. It should have a consistency of a hardboiled egg, just bouncier. You might find it can give a little hop, or even stick to the ceiling or the wall for awhile if you throw it. But it’s not totally indestructible – bounce gently, otherwise it can explode!
- Turn on the blacklight. You’ll notice that thanks to the highlighter, the egg should give off a bright, glow-in-the-dark-esque green glow. If you don’t have a blacklight, you can still do this experiment, you just won’t be able to see the green glow of the egg. If that’s the case, you don’t have to add the highlighter ink at all. You can just have a clear bouncy egg!
Why It Works:
There are two different things at play here. First, the vinegar is able to break down the egg’s shell, which is made of a calcium carbonate. When that material mixes with vinegar, a chemical reaction occurs to create carbon dioxide, and leaves behind just the membrane.
Additionally, osmosis is at play. The egg has a membrane, and membranes act in the interest of balance. So when the shell dissolved, the membrane worked to find balance. The vinegar solution traveled to the membrane through the process of osmosis, and helped to turn the whole egg a glowing green!
About the Author
Rachelle Dragani is a freelance writer based in Brooklyn with extensive experience covering the latest innovation and development in the world of science. Her pieces on topics including DNA sequencing, tissue engineering and stem cell advances have been featured in publications including BioTechniques: the International Journal of Life Science Methods, Popular Mechanics, Futurism and Gizmodo.