Year 5 participated in Science Week. This involved taking parts in lots of exciting experiments.

Firstly, we looked at how to make lava lamps using vegetable oil, food colouring, water and Alka-Seltzer tablets. We found out that oil is hydrophobic -it will not mix with water even if you
shake the bottle. The Alka-Seltzer tablet reacts with the water to make tiny bubbles of carbon dioxide which are lighter than water.
The bubbles attach themselves to the blobs of coloured water, causing them to float to the surface. When the bubbles pop, the coloured blobs sink back to the bottom of the bottle.

We also looked investigated liquid densities using different types of liquid – washing up liquid, coloured water, surgical spirit, oil and honey. We concluded that the honey was the most dense.

For our final experiment, we made balloon kebabs! We had to push a wooden skewer through both ends of the balloon without popping it. Most of the balloon is stretched evenly, but there are two points where the rubber is least stretched. The tied section and the darker patch at the opposite side of the balloon have the lowest surface tension. Most of the balloon is under high tension, so attempting to push the skewer through just makes the balloon pop. At the low tension sections it is possible to make a small hole without breaking the overall surface of the balloon.

We had lots of fun!