Greenfield Primary School
Water Cycle: Evaporation and Condensation
We have been learning about solids, liquids and gases in our science and reversible and irreversible changes.
We explored dissolving by putting salt into water. At first, the salt dissolved (we said disappeared at first but then we learnt the proper scientific word). However, when Mrs Wright added more and more salt, it stopped dissolving! We learnt that this was called 'saturation'. When Mrs Wright stirred the salt and water some more salt disappeared but we had to add more water to make all the salt dissolve again. Then we had a problem... Mr Ralph wanted his salt back! Eventually we suggested heating the salt solution. This caused the water to evaporate and left the salt behind. We then gave Mr Ralph his salt back so he could use it on his chips! We know that this was a reversible change.
Look at the salt that was left behind when we evaporated the water off.
As part of this work we have also explored the water cycle. We made our very own mini cress gardens to which demonstrate a mini water cycle in our classroom. We weren't sure that they would work so it was very exciting when the seeds began to grow. As the days went on we saw condensation forming on the cling film - this acted as rain to water the plants!
Look at our gardens after 7 days!
Planning an investigation
After learning about evaporation, we designed our own investigation to find out whether we could alter the rate of evaporation depending on location of the water.
We decided to place some water in three different places around our classroom: The window, the bookcase in the corner and in a cupboard. We then got 6 identical beakers and put 100ml of water in each beaker and placed them in pairs in the three places. We put cling film on top of one of the beakers in each area. We said that the cling film beaker would be a control and we predicted that no water would evaporate from these beakers.
We then made predictions about which beaker would lose the most water... We designed a table together on the Interactive White Board to record our daily measurements. We are excited to see what happens!