Our focus Science day was to experiment and explore what happens to ice. We did an experiment to see if we could insulate and create an ice shelter made out various materials. We used tinfoil, cotton, tissue paper, polystyrene and paper.
We found that the tinfoil stopped the ice melting the longest.
In the afternoon we tried out hand at making our own ice cream!
The same reason salt is used on icy roads and why salt is mixed with ice to make ice cream. Salt causes the ice to melt. When salt and ice mix, the freezing point of the ice is lowered and the freezing point reached depends on the amount of salt used. The more salt is added, the lower the temperature can get before the saltwater solution freezes. For example, water will normally freeze at 32℉ (0℃). A 10% salt solution freezes at 20℉ (-7℃) and a 20% solution freezes at 2℉ (-17℃). When salt is added to ice (or snow), some of the ice melts because the freezing point is lowered. Keep in mind, however, that heat must come from somewhere to melt the ice. The heat that causes melting comes from the surroundings and, in this case, it’s from the warmer cream mixture. By lowering the temperature at which ice freezes, you were able to create an environment in which the cream mixture could freeze at a temperature below 32℉ (0℃) and become ice cream. The shaking (or stirring in an ice cream maker) moves the warmer cream mixture from the inside to the outside of the bag so it can freeze evenly. That way you make a smoother product. It also adds air to the final product so it’s fluffed up a little bit.
If you’d like to make your own ice cream. check the link.