Are ice cubes in China are safe to use?

Science project dealing with regular ice cubes and a plastic cup?

• Hey Y!A! Ok so my little brother has this science project he has to do for his 3rd grade class. They've been learning about conductors and insulators, and their project is to design and create a cup (using a regular see-thru plastic cup that all of the students got!) that will block out heat and keep 3 ice cubes solid. They have to use the plastic clear cup everyone got, but they are allowed to decorate it to help their project in any way! They pretty much have to figure out which materials and colors can keep their ice frozen the longest, and can best block out the heat. dry ice obviosuly isnt allowed b/c the teachers are going to use the ice for the punch they will serve later to everyone. Soooo basically the rubric says: the materials used should demonstrate that the student has knowledge of insulators and heat resistant colors the cup should be modified in 2 or more ways My brother came to me asking for help, and I honestly cannot remember doing such a lame project when I was in 3rd grade... UGHHHH. so please help me out Y!A!!!! thank you!

• Answer:

  Well, you haven't stated what other materials your brother could use besides colors (paints). If only paints were to be used, Silver paint on the outside, as a base coat, then white paint. This gives you 2 modifications (maybe). However, if other materials can be used, try wrapping the cup in aluminum foil (set the cup on the foil (shiny side down) and bring the edges to overlap the top), then take a paper towel, folded like the foil, but in several layers, then wrap the whole thing in aluminum foil again. You could even make a cap for the cup, which will help keep the ice frozen. The more layers, the better the insulation. The outer foil will reflect heat away, the paper towels act like insulation, trapping air (a good insulator), and the inner foil is a reflector of any heat that gets past the first 2 layers. I've used this method to keep canned beverages cold for up to 6 hours at room temperature. Oh, and if you have it at home, put it in the freezer the night before you take it to class (kinda pre-charging it)