Science Week: Colourful Science from GMIT

We are really enjoying Science Week 2020.

Today we tried out our science bag from GMIT.

It had two wonderful experiments, and three interesting videos.

We watched a scientist examine the stomach contents for items of plastic, which helped us realise just how important it is to keep our beaches litter free.  We were sad to hear that many sea birds die from eating plastic that is thrown on the beach and ends up in the sea.  We will try to keep our litter in our bags or pockets and we might even go litter picking on the beach from time to time.

Our first experiment had to do with liquid density.  The more dense the liquid is (in our case water with sugar), the more it sinks to the bottom of the jar.  We were able to add different amounts of sugar to cups of coloured water, and then use a pipette to add the different colours of water to our glass jar.  Blue had the most sugar (5 spoons) and so sat at the bottom of the jar.  Yellow had the least sugar (0 spoons) and so remained at the top of the jar.  Green (3 spoons) and red (1 spoon) sat in the middle.  We ended up with a nice rainbow jar of water.  We could relate this to why it is easier to float in sea water than in fresh water.

Our next experiment had to do with surface tension.  Each table had a plate of milk.  Using pipettes drops of food colouring were put onto the plates.  Then using a cotton bud dipped in wash-up liquid we watched as the surface tension of the milk was broken and the drops of food colour rushed to the sides of the plates.  This was very impressive.  Now we understand why bubbles and raindrops always make spherical shapes if they can, and why pond-skaters and other little bugs can walk on water.

Lastly we tried leaving sweets (M&Ms and skittles) in plates of water and milk.  We noticed that the colours ran more quickly in the plates of milk than the plates of water. We also noticed that putting a cotton bud with washing liquid into the middle of each plate had a different result when put in water rather than in milk. The wash up liquid in milk caused the surface tension to break and the colours to run away from the centre of the plate. But the wash up liquid in water was the exact opposite:- it caused the colours to race more quickly into the middle of the plate.

How interesting.

Thanks to Galway Science and Technology Festival 2020 and to GMIT!