Science At Home : 2 Fun Experiments!

It’s high time I posted about fun science at home! I’ve got two experiments outlined below. I admit that it was difficult to come inside. The weather and fall colors are gorgeous.

Fall foliage
No, this is not my yard.

Along with fall comes the inevitable raking. Good thing I have Louie to help! And boys to bribe.

These experiments have minimal supplies, so you won’t even need to to to the store first! Especially if you’ve got as many drawers of junk as I do. (which I also ignore!)

The experiments will make great practical jokes.

Louie on fall clean up
Louie likes fall clean-up

Junk Drawer! Science At Home

In fact, I bet if you rummage around in your junk drawer, you’ll find what you need! These STEM science at home experiments will cost zero dollars! And they’re fun. 

You’ll look like an expert because I’m explaining the ‘why’ behind the science.

Time to impress your posse with science at home! 

Experiment # 1 : Spinning Straws

Spin a straw with no hands!

Supplies that I bet you have in your junk drawer!

I found that a rounded bottom works best, to decrease friction. You’ll see in my video, I use a flat bottomed glass. (Go figure.)

You won’t want to actually use these after the experiment…you’ll see why shortly.

Louie didn’t love this part.

Louie would rather be raking.

Steps to Spinning Straw Science Experiment

1. Place your glass upside down on a smooth surface
2. Use Your Head!
Take the straws and rub them on your head 12 times.
Louie didn't like this part.
3. Set one of the head-rubbed straws on the glass.
4. Bring the other head-rubbed straw near the first one but don't let them touch.
See my video below!
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Video of Spinning Straws

The Science Behind Spinning Straws

Two words :

Static electricity is the build-up of an electrical charge on the surface of an object. The reason that it’s called static electricity is because the charges stay in one area for some time. They don’t flow or move to a different area.

What are charges, exactly? Electrons!

 

When you rub the straw on your head –or against Louie’s hair– the electrons jump! Both straws gain electrons from your hair!

Since both straws have extra electrons, they are both negatively charged.  Like charges repel each other. Hence one straw pushes the other away.

Louie and straws
Louie is afraid of losing his electrons!

Since your hair lost electrons to the straws, is your hair now negatively or positively charged?

POSITIVELY CHARGED!

This science experiment at home is demonstrating the repelling of like charges! 

If you bring the charged straw close to your hair, it will stand up. Why?

Because like charges attract!

Remember your hair is now positive because it lost electrons to the straw.

There are many ways to make electrons jump. 

Rubbing your feet across a carpet causes the electrons to jump onto you. More and more join your trek across the carpet.

Eventually more electrons don’t want to come up on you because you’re so charged up. You end up with a high voltage, about 20,000 to 25,000 volts.

That’s serious power at your fingertips, considering a normal electrical outlet on the wall is only around 100 volts of electricity.

And bolt they do. You touch the more positively charged doorknob–after all you are full up with electrons– and get a shock!

Lighning
Credit Kelly DeLay

Static electricity works best on cold, dry days. This is why we get more shocks in winter. If it’s humid, the way it is in the summer, there is more water vapor in the air. 

Water molecules are polar, meaning they have a positive and negative side. On a humid day, the electrons from the carpet will jump to the positive side of the water molecules in the air, instead of to you. 

Water molecule
Polar water molecules

I discuss water properties in my book, Chemical Reactions, coming out in 2021. And in this post, too.

Fun Experiment # 2: Do Not Open or The Water Bottle Trick

Who doesn’t love a challenge? The second someone tells me NOT to do something, I’m tempted. I shouldn’t call science a trick, but with this one, you can trick your kids, guests, siblings, anyone you please. With science at home! Time to trick your posse….

Science at Home 2 Fun Experiments

Supplies that I bet you have in your junk drawer or in this case, the recycling bin!

It’s actually not empty. What is inside this bottle?

Materials portable water bottle
Supples for water bottle trick

Steps for Water Bottle Trick

1. Poke a hole into the side of your empty water bottle
(You can put tape over the hole if you're taking this somewhere else, but it's not necessary)
2. Fill the bottle with water and quickly put on the cap
Take the tape off (if you used it) Unscrew the cap!
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Video of Water Bottle Trick

The Science Behind the Water Bottle Trick

First, let's answer that question

Is the empty water bottle empty?

NO!

The empty water bottle is full of air!

When you pour water into the bottle, the molecules of air that once occupied the bottle come rushing out of the top. You don’t notice this because molecules of air are invisible. 

Likewise, when you pour water out of a bottle (thanks to gravity) the water rushes out. The other action that’s occurring is that air rushing into the bottle.

Think of it as an even exchange of water for air.

When the lid is uncapped, air sneaks in through the top of the bottle. The air pushes down on the water (along with some help from the force of gravity), and the water squirts through the holes in the bottle. 

Louie drinking from a bottle
Louie disregarded the warning

This makes a great practical joke for kids. They’re learning science and having fun. 

Surface Tension

You might ask why poking a tiny hole in the side of a bottle would not cause it to leak. It would if  air molecules can sneak into the bottle. However, when the lid is on the bottle, air pressure can’t get into the bottle to push on the surface of the water.

The water molecules work together to form a kind of skin to seal the holes—it’s called surface tension. (I talk about this in that other post, too)

Surface tension occurs because water molecules are attracted to each other! Remember that water molecules are polar, meaning they have a positive and negative side. Opposite charges attract!

This is called cohesion. (the intermolecular attraction between like-molecules)

Science At Home Cohesion facts for kids
Cohesion!

Water really is

Science at Home the power of water
Gorgeous afternoon hike

Some insects use surface tension to stay afloat! They are lightweight enough so they don’t disrupt cohesion. (Larger animals incorporate other adaptations to help them stay on top of the water surface)

Water strider
Water Strider wikimedia commons

I bring a water bottle along on walks with Louie and untape the hole so he can have a little drink. The tape is necessary in this case, because if I grab the bottle, exerting pressure on the side of the bottle will force water out of that hole. 

This science trick is portable!

And there we go! Science at home with 2 fun experiments. Go ahead, trick your friends!

Let me know if you try either of these science experiments at home !

Louie vastly preferred the water bottle experiment to the spinning straws experiment. 

 

Which experiment do you like best?

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66 thoughts on “Science At Home : 2 Fun Experiments!”

  1. These are great experiments to try at home. They’re very similar to some in Flora’s bi-monthly Letterbox Lab subscription boxes, but getting kids involved in fun science at home is always a good thing!

    Reply
  2. These look like some really fun experiments to do with our nieces and nephews. I’m going to have to give them a try – especially the water bottle trick. I’m sure that they would have WAY too much fun with that one! Thank you for sharing these… I love that they use nothing but the items we have kicking around the house already.

    Reply
  3. Interesting experiments! And with this, I just reviewed some chemistry, hahah 🙂 I might try these.

    Question, though: since you didn’t fill the bottle with water completely, is the remaining part of the bottle filled with air?

    Thanks!

    Reply
    • Great question! I did fill the bottle completely and a bit dripped out until the water cohesion took hold. (I was taping the videos myself, a personal challenge!) So yes, there is some air in the bottle exerting pressure but the cohesive properties are keeping it in balance. Thanks!

      Reply
  4. My favourite is putting water on a flat plate, placing 3 coins in the water, lighting a match and placing it on the coins and then putting a pint glass over the top. The fire burns all the oxygen and creates a vacume, sucking up the water into the glass.

    Helen

    Reply
  5. Great ideas – these definitely impressed me! I didn’t find science too interesting when I was at school, but when you apply it to fun situations like these it’s much more interesting. P.S. your dog is adorable!

    Reply
  6. These are very fun experiments to try out, especially with being in lockdown, it will help people to do something fun rather than doing nothing at all 😁 Science is fun that’s one thing my teacher taught me at school.

    Reply
  7. You can’t go wrong with some science at home! The static electricity one was always fun – It helps kids understand why we get that shock when we get clothes out of the dryer and such. Love the science with this!! Thanks for sharing!

    Nancy ✨ mdrnminimalists.com

    Reply

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Susan Berk Koch
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