Today we made volcanoes in science club. First we buried bottles in sand and filled them with vinegar, washing up liquid and food colouring. Next we added bicarbonate of soda which reacts with the vinegar to produce a gas called carbon dioxide. The gas pushes the washing up liquid and food colouring out of the bottles and it looks like lava running down the sand.
At science club we made patterns by mixing milk, glitter, food colouring and washing up liquid! Detergents such as washing up liquid like to join together water and fat (or grease) which is why they are good at cleaning dishes. In our experiment the washing up liquid tried to get the water and fat in the milk to mix together. As it does this it creates swirls and patterns in the milk as the different colours mix together.
Fizzy drink fountains
Coke and lemonade are ‘carbonated’ drinks which means they have carbon dioxide dissolved into them. The fizz we get from these drinks is caused by the carbon dioxide coming out of the drink as small bubbles of gas. There is actually a lot of carbon dioxide dissolved in a fizzy drink and if we can get it to all come out of the drink very quickly the results can be very impressive!
Mentos sweets might look smooth but they actually have a very rough surface as the microscopic level. These bumps on the surface act as something called nucleation sites which cause the carbon dioxide to come out of the liquid as gas bubbles. As the Mentos sinks is causes more and more bubbles to be formed!
Floating and sinking
This week, year 1 and 2 investigated floating and sinking. We found out that an orange with its peel on (heavier) floats and when the orange is unpeeled (lighter), it sinks.
The orange with peel floats because the peel is porous and filled with tiny air pockets. Those air pockets make the orange less dense than water and cause it to float. The other orange without a peel does not have these air pockets. It is denser than water and therefore it sinks in the water.