Exploding Lunch Bag

For those of you who know my kids well, they frequently (always) get into the kitchen, take out different equipment or ingredients and ask (demand) if they can make something.  Last week it was a banana and honey smoothie in the blender - end result was this smoothie for 2... or perhaps for 15!

This week it was the bicarb of soda.  They wanted to make a volcano again... You can imagine my delight when - just five minutes before lunch is ready, I'm finishing the cooking and setting the plates - I hear (on repeat) "I want to make a volcano.. I want to make a volcano.. Muuuumm, I want to make a volcano!" Perfect timing, kids! Thanks!

 It's been a while since we've worked with bicarb so I thought why not?

 

All you need for this one is:
One small zip lock bag
Bicarb of soda
Warm water
Vinegar
Measuring cup
Vinegar

You will need to do this outside - it gets a little messy... and if it's not a good day outside then do it in the kitchen sink or the bath!

Pour 1/4 Cup of warm water into a bag.

Add 1/2 a cup of vinegar into the bag.

Lay the tissue out flat.  Put in 3 teaspoons of bicarb of soda into the middle of the tissue.

Wrap the tissue around the bicarb of soda - only do this lightly - it will help buy you time when you combine the bicarb to the water/vinegar mixture.

Now really quickly zip up the bag and watch what happens!  These pictures were taken the first time we tried the experiment - it didn't work as well as we had hoped but it sure was fun!

 

 

The mixture started fizzing up ...

 

 

The bag started expanding...

 

And expanding - until it got really firm to touch...

 

The kids were so excited but really scared so they kept on running away, waiting for it to explode...

 

Then they ran back to it to see if it did explode...

Until finally we realized the bag had popped - just not how we thought it would! A small hole in the bag- created either by a blade of grass or the fact that the bag had expanded so much that it had ripped the bag.

We did try this experiment again - this time I shook the bag quickly after adding the tissue and bicarb  to the water/vinegar mixture and threw it on the ground (not the grass).  It exploded much more quickly and the boys were absolutely going crazy at what happened - they loved it! If I had more camera battery I could have shown you their faces - they loved it!

Nothing like a little Chemistry to please the senses! What happens inside the bag?  The baking soda and the vinegar eventually mix and when they do mix, you create an acid base reaction and the two chemicals work together to create a gas, (carbon dioxide - the stuff we breathe out). It turns out gasses need a lot of room and the carbon dioxide starts to fill the bag, and keeps filling the bag until the bag can no longer hold it any more and, POP!

Thanks, Science Bob for this cool experiment!

Caution: Men At Work!

The thing about kids is you never know what is going to happen until you actually try it. Take this investigation, for example... I thought it could either go really well, and the kids would get really into it, or it could go really bad and they would have no idea and it will all be a waste of time. Sometimes you've just got to bite the bullet and give it a go.  In this case - it went both ways... what I wanted them to do was similar to what they did, but their version of it was just as fun!

So my thought process was this. The other week we did the "Build A Bridge" experiment.  It went really well with E, but not so well with N. He was a little young to understand the concept of "Design and Make". That being said, it has renewed his interest in bridges and always talks about them now. So I wanted to do another investigation that involved bridges.

What you need:

• 3 or 4 pieces of Cardboard or thick paper - each one folded a different way.  One was just a flat strip of cardboard. One was a corrugated piece (zigzag).  One was an arch (you can see a better example of the arched bridge we used in  another picture.  The final one was a girder shape (picture of the girder shape is next to this picture).   

 

• 2 cups the same size
• Plastic counters to act as "cars" ... We started off using beads (with flat bottoms), then changed to slices of carrots

First I showed the kids how the two cups were the pylons for the bridge.  I asked them to use the cardboard pieces to build a bridge that holds lots of cars.

Here's how it went...

 

They used each piece of cardboard separately first, then placed the beads on their bridge to see if it would hold.

 

The more beads or carrots their bridge held, the more excited they got. 
However, the more beads their bridge held the more likely they all fell off so we had to change our "cars".  We decided to use chopped up carrot pieces instead!

(I like to think of this as a creative cheat! hahaha)!

The sticky tape came out and pretty soon they were both creating their own bridges using a few of the different examples I had given. They both worked out that the bridge was sturdier if they put on lots of layers of cardboard rather than just one. 

 

By the end of it, the kids had built lots of bridges but then became hungry... and suddenly the carrots disappeared ;)

How is this science? The strength of something isn't just about what it is made up of - the shape is important too.  Folding flimsy card into a beam makes it rigid and strong.

The corrugated bridge is made up of triangle shapes which are the best at holding heavy loads.  A triangle is really strong as it directs weight straight to the ground.

Thank you, Mini Scientist In The Kitchen (Lisa Burke) for this wonderful idea!

Build A Bridge And Get Over It!

One of my favourite parts to the Science Syllabus is the "Design and Make" component.  It is a chance for kids to use their creativity, problem solving and reasoning skills.  I always LOVED watching the kids get creative in the classroom - there was always so much discussion and so many busy little people.  I ignored the messy classroom and instead embraced the creative chaos!

I wanted to introduce my kids to the concept of designing and making.  I began by giving them a couple of things that I thought would help them complete the task.  These included:

• A lid that came off a "city scene" box that my kids had.  It had a picture of grass and two lakes.  You can use anything to set the scene - you could even cut up some paper to make it look like water, or you could use some tape to make a busy road
• Paddle pop sticks
• Playdough
• Toilet paper rolls
• Tools (I thought the tools would capture their interest - and it did!!)
• Cardboard
• Pencils
• Small cars/trucks

Note: You do not need to use anything in this list - just pick up things from around your house that you think will work - it's surprising how creative your kids will get!

I then set the scene...

This little truck wants to go over the lakes... Look how the truck drives around the lakes - it's taking so much time! Look! It's getting stuck because there is not enough room to move!  The truck wants to go across the water - how can we get it across the water?

E: A boat! Or a bridge!

He was right onto it!

Usually when we facilitate a design and make session, the kids are asked to "design" by drawing a plan of what they are going to do before they actually build it. Because this is the first time my kids have done this, I decided to swap it around and get their creative juices flowing first by "doing" then drawing what they did.  This is how it went...

At first they were a little lost - they poured all of the paddle pop sticks onto the water and E proudly said that that was their bridge. Rather than take them all off and show them another way, I got the truck and showed them that the truck still couldn't get over the water because all of the paddle pop sticks were moving around and it was too bumpy for the truck.

I asked them to think of another way to build a bridge that wasn't so bumpy and...

Great idea! But the truck finds it really hard to climb up the edges of the bridge. What do we need to help the truck to get up?

 

Awesome idea!! Paddle pop sticks sloped onto the container and some play dough to hold the "ramp" together. E took it upon himself to test the bridge and check if it was easier to travel up... It was! I love love love everything that happened there - problem solving, making, testing, re-making, retesting, fixing, thinking, questioning... This activity has it all! 

Extra challenge for E - can you make another bridge using different materials?

 

This is what he came up with ...

 

4 toilet paper rolls with cardboard on top. Initially there was only 3 toilet rolls (N was busy with the 4th toilet roll I had initially put out) so he made me get another one so there was an even amount on both sides!

Pretty creative! And so much fun! I love the look on their faces when they are engaged in these activities!

 

You might notice that E was the only one doing this experiment. At almost 4 years old this experiment was more suited to E than N who is 2 and a half. Having said that, N came up with his own little experiment - throwing a big blob of play dough through a toilet paper roll and seeing how far the play dough flew through the air and onto the floor... Hours of fun and lots of giggles! It kept him amused for ages! Love that :)

 

The beauty of the design and make process is that the list of things to design and make is endless - building a bridge is just one idea. Maybe you would like to design and make a shelter for a pet? The houses in the story The Three Little Pigs? An obstical course for a younger sibling? An obstical course for a dog? A car? A park?....should I keep going? 😉

Worm Farm!

The sun is back and the kids are finally getting their dose of Vitamin D ... under the sun and loving it!

What better way to celebrate the sun coming back than to spend some quality time in the garden - digging, picking fruit off the trees and enjoying each other's company.  So it was off to E and N's great-grandparent's house for some lunch and gardening... And the beginning of our very own worm farm!

All you need to make a worm farm is:

A clear bottle or container
Some hay, leaves, or mulch
Soil
Worms
Fruit/vegetable scraps
Black paper

First, the kids began digging the soil.  The kids always enjoy doing this and can keep them entertained for ages - they even have a special spot in the garden where they can dig so that they don't dig up any new seeds or destroy any of the growing crop already in the garden. 

While they were doing that I cut the top off our bottle so that we could easily put in all the things we needed to make the worm farm.

Pretty soon the kids got to some moist soil and this is where the fun started... Worms galore!

We found lots of worms - the kids were really excited and were describing them

"Look mummy! That worm is so small, it's so cute!" (Never thought I'd hear that! Haha)
"That worm is dancing!"
"This worm is so fat!"
"Yuuuck!"
"That worm is digging back down in the dirt.  Come back, worm!!"

We put some soil into the bottle and added a couple of worms. 

Then a layer of hay that mum had in her garden.

Then continued that pattern until we reached about 3/4 of the way up the bottle.  The soil was really moist because of all the rain we have had, but if yours is dry you may want to use a spray bottle to wet the soil.

We taped the top of the bottle back on and the kids put their fruit scraps in as compost.

Worms are nocturnal, so it's really important to keep their environment dark, otherwise this observation wont work well.  We taped black paper around the bottle and kept the black paper on for 2 days.

When we took off the black paper and saw what the worms had created...

It was a little hard to point out initially, but finally the kids saw and understood the little tunnels the worms made.

It's a little hard to see in this picture, but you can see a worm made tunnel just under the first groove in the bottle, slanting from the left to the right.  There were lots of other tunnels just like this one around the bottle.

Once I pointed it out to them the kids turned the bottle around over and over again, pointing out all of the worm tunnels.  They even noticed that the pear scraps that they had put in had turned brown.

We kept the worms for a couple of days and then released them back into the garden - bye bye worms!

The best part about this experiment?
We had just made the worm farm and what did the boys do? Straight to the cumquat tree, picking fruit off the tree and eating them fresh off the tree with their great - grandfather.  Love!  :) ...