Melting ice

Working with Mr Cranston today, the children looked at factors affecting the rate at which ice melts – the size of the ice block, its shape and the temperature of the surroundings.  

An interesting side note was that the level of the water in the containers did not increase after the ice had melted.   We discussed how this was because the ice was already floating in the water and displacing the same volume of water that it would contribute when it melted.  (You could try this out at home if you want convincing.) So, melting ice bergs will not raise the sea level, although the melting of land ice will.

States of matter – weekend challenge

We’ve begun a new science topic by examining a variety of solids and liquids and thinking through the differences between them.   You can see what we came up with below. 

We also began to talk about the different arrangement and movement of the particles making up solids and liquids.  This week’s challenge – for young scientists who want to develop their thinking and knowledge on this topic – is to look at this explanation of the difference between solids and liquids (and gases) and see whether you can use it to explain some of the differences between solids and liquids that we observed.

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Doctor swallows a camera

We finished our science project by looking at the human digestive system.  We each took a bite out of a Jacob’s cream cracker and let it soften in our saliva.  We used our tongues to push the food around our mouth and then into our oesophagus for the 7-second journey to our stomach.  Then we used this informative and entertaining video to find out what happens next: Doctor swallows a camera

It would be great if you’d get your son or daughter to show it to you and explain what’s going on.

Science results

Five days after immersing our eggs in vinegar, orange juice, coca cola, tea and water, we examined the results and drew conclusions.

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Egg immersed in vinegar

Here are some of Sam, Hollie and Tom’s detailed observations and conclusions.

  • The liquids had different effects on the eggs most of the time.
  • The vinegar dissolved the egg shell the most because it is an acid.
  • In the orange juice, the egg shell only half dissolved because orange juice is less acidic than vinegar
  • The egg shell in the cola only dissolved a bit.   Even though it contains sugar, it isn’t a strong acid.  The sugar damages your teeth when it mixes with bacteria in your mouth.
  • Water did not damage the egg shell and would be the best to drink for your teeth and health.  Water did not change anything because it is neutral.
  • The tea stained the egg but did not dissolve it.  (Whenever you spill tea at home it makes a stain.)
  • Order of strongest acids:
    •  vinegar
    • orange juice
    • coca cola
    • tea and water are not acids
  • Toothpaste helped to protect the eggs from acid and tea staining.

 

 

Egg-speriment! – as Lynden put it

We began an experiment today to investigate the effect of different liquids on tooth decay.  Using eggs to represent teeth (because egg shells have a similar chemical structure to tooth enamel), we placed eggs in five beakers containing five different liquids: vinegar, orange juice, coca cola, tea and water.  We’ll look again in a few days to see what’s happened to the egg shell.   

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We also smothered a second set of eggs with toothpaste and put these into different beakers containing the same five liquids to see whether this makes a difference.

The children have all made predictions about which liquid will cause the greatest change to the egg shell.  Vinegar, orange juice and coca cola are all acids. Budding scientists, wanting to carry out some additional research, could find out which is the strongest and this might help us to explain our results.