Harrison Primary School

Time for Science Club to make some more slime … this week, Group 4 chose to make the stretchiest, slimiest version from PVA glue, shaving foam and eye wash solution.

We found that it would behave like a solid when it was squeezed and pressed, and like a liquid when the pressure was removed.

Science club Group 4 were investigating spinning tops this week. We made spinners from an old CD, a marble, a bottle top and some blu-tack in the same way as Group 2 did a few weeks ago (see the post http://harrisonprimaryschool.primaryblogger.co.uk/2019/11/10/spinning-around-2/ )

We talked about the best design for the spinning top, and how to reduce the amount of friction so that it spun for a long time.

This time, we decorated the tops with silver and gold holographic paper on a background of black card.

We switched off the lights and shone a torch on the spinners …

As the spinners twirled around, the holographic card refracted the light from the torch and rainbow colours appeared.

The challenge : can you power a calculator using just ordinary fruit and vegetables and a few everyday items? Science club had to make a battery for a calculator and work out some complicated sums, all within a time limit of just a few minutes!

First of all, we investigated how to link up a couple of potatoes with some copper pennies, zinc nails and a few pieces of wire. The juice in the potatoes causes a small amount of electricity to flow between the penny and the nail and we could measure the amount of voltage.

Then we attached the potato battery to the calculator and found there was just enough electricity to run the calculator.

Next we tested a range of different fruits and vegetables and found that they could all be used to make batteries.

Even brussel sprouts!

Finally, we powered the calculator using fizzy cola and crisps.

Science Club enjoyed making fizzing volcanoes using the reaction between an acid (such as vinegar or lemon juice) and bicarbonate of soda…

The reaction produces carbon dioxide gas which makes the mixture foam and froth.

We set up mini-volcanoes and explored using different colourings in the liquid to produce interesting coloured lava, and investigated different containers for the volcano crater.

Yellow lava

Blue lava

Multi-coloured lava!

In Science Club, Group 3 found out how to change a liquid into a solid without chilling it or freezing it. We were exploring the strange properties of “Oobleck”, a mixture of cornflour and water.

We discovered that when the mixture is pressed hard, it forms a solid

But as soon as you let go, it turns into a liquid again and flows through your fingers and forms a puddle.

This happens because the mixture is formed from tiny starch granules in suspension in the water. They lock together when they are pressed firmly. As soon as the pressure is released, the granules can slide across each other and the liquid can move again.

So how would you escape if you were caught in a giant pool of Oobleck ? (or quicksand, which behaves in a similar way). We experimented with plastic figures to find the best way to rescue them.

In Science Club this week, we looked at fizzy reactions that take place when sherbet ‘flying saucers’, effervescent tablets and bath bombs are added to water. They contain sodium bicarbonate (baking soda) and acid, which react together to produce carbon dioxide gas and produce lots of fizzing and frothing.

We mixed lemon juice (an acid) with bicarbonate and placed a stretchy disposable glove over the top of the glass so the gas could not escape. What would happen?

The glove filled up with carbon dioxide and waved at us!

And then …

We investigated changing the amount of acid and bicarbonate, and compared lemon juice with different types of vinegar.

This week, Science Club have found how to turn flour into playdough.  To do this, we needed to make the starch granules in the flour expand and fall apart by heating them with boiling water. We mixed flour, salt, oil and a few other ingredients with the boiling water and watched the mixture thicken and turn into a stretchy dough.

We made our playdough more interesting by adding food colouring, and peppermint flavouring (although it definitely isn’t something you can eat, there is way too much salt in the recipe!).

Once the hot playdough had cooled down, we got creative with the playdough tools …

Now what shall we make with the playdough?

This week in Science Club we have been looking at how to make spinning tops. We looked carefully at some spinners to see how they were designed to produce a low amount of friction so that they could keep on spinning for a long time.

The challenge was to investigate how we could make our own spinning tops from recycled materials, using a CD, a marble, a bottle cap and some blu-tack.  By sharing our ideas, we worked out the best way to put these together and produced spinners that kept on going and going ….

Next we put some pre-printed patterns on top of the spinners and watched how they changed when spun around. Unexpected colours and patterns appeared!

We designed our own patterned disks

Our own colourful designs

Science Club looked closely at nappies this week. Some brands of nappy cost three times the price of the supermarket own-brands. But do they absorb 3 times as much liquid? We set about investigating this.

We compared how much liquid each type of nappy could hold, by placing the nappies in trays of colourful alien wee.

Surprisingly, the supermarket nappy was just as good as the more expensive brand!

Both nappies could hold a lot of liquid, because they contain small granules of “Super Absorbent Polymers” which can absorb lots of water.

We took the nappies apart and had fun handling the squishy contents.

This week, Science Club explored how to make some strange sounds from a piece of string and a paper cup. We attached the string to the cup and decorated the cups with different designs.

When the string was rubbed with a piece of damp cloth, the vibrations moved up the string to the cup and the sound was amplified. We produced some strange screeches, cackles, clucks and squaws ! Just listen to these …

Then we explored how we could to change the loudness and the pitch of the sound. A small cup with a thin string made a screech like a little mouse. A big crate with a larger, thicker string sounded like a distressed cow!

We also found out about  “musical roads” where special raised markings have been set into the road surface.  When a car drives along the road, it vibrates and makes a musical note.  The sound changes depending on how far apart the road markings are placed. So when you drive along the road at a steady speed, you can hear a musical tune!

See and listen to it here : musical road video