Kitchen Chemistry - The Coloured Ice Cube Experiment

Last week, as part of our Inquiry learning 'Kitchen Chemistry' we carried out an experiment on a coloured ice cube. We used our growing observational skills to make statements, complete drawings and make wonderings. It took around 15 minutes for the ice cube to melt completely. We also noticed that condensation formed on the outside of the jar and bubbles came from underneath and on the sides of the ice cube.
We wondered what would happen if you changed the water in the experiment. This is called changing a variable. We wondered what would happen if:

• we changed the temperature of the water
• we added salt to the water
• we added white vinegar to the water

This week we tested our different ideas. We found that:

• the hot water made the ice cube melt a lot faster! It only took 3 minutes to completely dissolve
• the vinegar looked a lot like our control sample, in that the colour dissolved slowly, creating lines of colour that sank to the bottom as well as colouring the water

The salt water was the most interesting. We noticed a colour change in the water from the moment we added and dissolved the salt. As the ice cube melted, a layer of red colouring formed on the top of the water. We discussed this and decided that it was because salt water is more dense than fresh water and the ice cube had fresh water in it so it sat on top. This made us wonder what would happen if we mixed the two waters together - would they separate again? We tried it and we found that they didn't. We had lots of great discussion today about what we saw and it was wonderful to see Room 7's curious minds in action!

Our control sample - cold water

Hot water - the ice cube lasted 3 minutes only!

White Vinegar

Salt water

Observation of a Candle

As part of our new Inquiry learning we became scientists! We used some of the skills that scientists used - observing, collecting, comparing and predicting, to see what happened to a candle when it was lit.
We already had some ideas about what would happen, but looking really closely and using our observation skills we found some new things that we hadn't thought about. We noticed that the flame of the candle was actually blue at the bottom and that the wax didn't dribble down like we thought it would.
We have had discussions this week about 'States of Matter' and we noticed that the candle was 'solid' but after it was exposed to heat it became a 'liquid' (wax).  We saw the heat affecting the air above the candle too.