Melting Away

This week we investigated what happens to the temperature of ice as it melts. We measured the temperature every minutes for 10 minutes, while checking to see if the water was solid, liquid, or gas.

Initially the temperature was a FREEZING -10° C. Not surprisingly the temperature started to rise, but then something funny happened.  As the temperature approached 0° C, it stopped changing. Yet, the ice was still melting. Clearly heat from the surroundings was being absorbed by the ice, but to look at the temperature, you'd never know it. Then, as soon as all the ice was melted into water, the temperature started to climb once again. 

From this experiment we learned two things: 
1) The freezing point of water is 0° C
2) At this temperature, the energy flowing from the environment into the ice is being used to change the water from a solid to a liquid, resulting in a constant temperature until all the water is in the liquid state.  

We see the same thing happen as substances move between liquid and gas states.

General Science: The Right Stuff

This week the kids had to design a spacesuit that could withstand the intensely high temperatures one might find on Venus. Lacking the funding to actually travel to Venus and not wanting to violate the Helsinki Declaration (ethical principles for research on human subjects), we used ice-pops instead of people and hot water instead of Venus. The kids made spacesuits using one of three available materials: tin foil, cotton balls, and bubble wrap. Each of the subjects was then placed in a plastic bag and then then submerged in hot water for 1 minute. Afterward, the kids opened up each ice-pop and measured how much of it had melted by pouring the liquid from each one into a graduated cylinder.