Elephant Toothpaste

So I decide to do the elephant toothpaste experiment last Saturday. There are many examples of this experiment done in labs and also using potassium iodide, not only is that stuff hard to get in an everyday shop but also very unsafe for little tikes. So a more kid -friendly version was needed. So instead of potassium iodide I get my mum hands on some dry yeast.

Oh yeah, that's the stuff! We begin the experiment per normal, get all the stuff ready and we pour all the ingredients into the bottle, stir a bit and wait for the fun.....
Nothing yet.
More waiting.
Go play.
More waiting.

ABSOLUTELY BUGGER ALL HAPPENED!!! Yeah sure there was a few bubbles but the experiment was a complete fail. So embarrassing. Do I need to tweak out all the measurements? Yes. Different yeast? More hydrogen peroxide? Maybe. Whatever the problem, filming failed hard. You can watch my fail here...

Failing elephant toothpaste

So here is the experiment that actually works quite well. I hope that you have better luck that I did at home. Don't be afraid though. Science is all about learning from your fails and doing it better next time. We are always learning!

Elephant toothpaste experiment.

1/2 cup of Hydrogen peroxide liquid (can be found at any chemist or hairdressing supplies shop)

3 baggies (or 3tbsp) of dry yeast. (however, if you can get your hands on some "wet yeast" that the bakers use, get a square of that. Works so much better!!)

Dishwashing soap (one squirt)

Food colouring

Hot water

soda bottle, clean and dry

plastic cup and spoon

tray for the bottle to be put into.

Goggles and some gloves (for the safety consious)

Please be advised that this experiment has a few dangerous products (the peroxide) and must use caution not to touch or eat the toothpaste.

Method:

1) Pour the hydrogen peroxide and dishwashing soap into the soda bottle and place onto the tray. Place a few drops of food colouring onto the top inner lip of the soda bottle.

2) In a plastic cup, place the yeast and hot water. Stir for 30 seconds till it makes a paste (that smells like feet)

3) Pour this yeast into the soda bottle and wait for the magic!!!

Dropping the science:

Each tiny bubble in the foam is filled with oxygen. The yeast acts as a catalyst to remove the oxygen from the hydrogen peroxide. Because this reaction is very quick, it creates bubbles/foams and heat. This is what's known as a exothermic reaction. If you feel the bottle after the foam stops forming, it feels hot. The foam may even steam!

Water Sandwiches (Bubble recipe)

We had some fun this Saturday with this experiment. Hunter absolutely has a thing about bubbles. Every chance she gets she wants to play with bubbles. But the pre-made shop bought bubble mixture can be rather expensive and goes like greased lightning the way she plays with them!!! So I decided to try out my home made recipe and see how we go.

Water sandwiches part 1

We made two mixtures to see which works the best. I call bubbles "water sandwiches" and I will explain why very shortly. 

Water Sandwiches Recipe

1 cup of dish soap ( keep the bottle handy in case more is needed)
Distilled water or tap water.
1 cup of corn syrup (but be very generous)
bucket or container with a lid.

We made two batches. One with distilled water and one with plain tap water to see which would work better. 

Method

1) Place all the ingredients into the bucket.
2) Stir.
3) For sweet results, let the mixture sit overnight. Unless you have a five year old screaming
 in your ear 'BUBBLES!!!!!!" over and over, a hour standing time should be suffice. 

Dropping The Science:

Bubbles are made up of three layers: soap, water, soap. The layers of soap on the outer and inner part of the bubble is called a soap film. (Wow, how original!) The middle layer that the water resides is trapped between the soap film "sandwiching" the water in place. When the layer of water evaporates, the soap film becomes unstable and collapses, also referred as "popping the bubble". The stronger and thicker the soap film skin, the less chance of the water sandwiched between the layers evaporates. That is the key for longer lasting bubbles!

Gotta looooove bubbles! I have linked the video of the bubbles we made below so you can check it out!

Playing with the water sandwiches

Fishbraid

Corn flour slime

So last week we filmed how to make homemade cornflour slime. Awesome stuff and so easy to make! We finished filming and the kids played with that mess for about a hour and half. There was so much purple everywhere, in Hunter and Rainer's hair, right down to his nappy! The beauty about the slime is that it's so easily washed off with water. so a nice bath afterwards got the kids in pristine condition. Click on the link below to check it out.....

cornflour slime

So here is the recipe for the slime in case it's hard to watch online as the footage sucks with me juggling how to do the experiment and children to boot ( mums and dads know this pain! )

Cornflour slime recipe

You need:

Cornflour ( about 2 boxes, depending on how much you want to make)
Water
Food colouring (any colour is good)
Mixing bowl ( and old tupperware or ice-cream container works)
Plastic spoon
Biscuit tray

Method

Place cornflour into the mixing bowl and add a little bit of water. (This is a great time to bring the kids in to get their mess on ) mix till it feels like a paste.

You will start to feel the mixture become slime-esque. it is now ready for a few drops of selected food colouring of your choice.

Now let the fun begin!
You can punch it, slide it through your fingers  or get stuck in it like quicksand!

Please note: DO NOT DISPOSE SLIME IN THE SINK!!! This will clog it up bigtime and you will have to explain to the plumber why a monster puked in your sink. no-no. Rinse the slime away after play out on the lawn with the hose or scrape it out and place into the bin accordingly. 

Dropping the science:

Cornflour has tiny starch particles that really like water. The water acts like a lubricant, when you drag your fingers slowly through the slime, the water can move easily between the starch particles. However, applying rapid force or pressure onto the slime (like a punch), it causes the starch particles that are almost touching each other to jam together and the water that was flowing between the starch to move out of the gaps causing it to thicken. This creates the slime to solidify. And hurt your hand if you punch too hard!

Cornflour slime laughs at the face of fluid dynamics.Fluids are gases and liquids. We have fluid that come in two categories. low or high viscosity. Low viscosity is the easy flow of liquid like water. High viscosity is the hard flow of liquid like cold honey. Cornflour slime is a good example of "shear-thickening fluid" where it can be low or high viscosity. Other examples of real world shear thickening fluid is toothpaste, blood,paint, pen ink and nail polish.