You will need:
- Two glasses (or plastic cups)
- Food dye
- Salt
- Access to a freezer
- Ice cube tray
Mix the food dye and water, put it the ice cube tray, put the ice cube tray in the freezer and wait… Now you have colored ice cubes!
Fill the two glasses with tap water. Take one of the glasses and mix in salt until the water tastes like sea water. Then, put one ice cube in each of the glasses and watch what happens. Where does the ice melt fastest? And why?
For advanced oceanographers: you can also use “clear” (not dyed) ice cubes, then seeing what happens is a little more difficult (and a little more exciting :-))
You can read about what happens – and why – on my friend’s and former colleague Mirjam’s blog “Adventures in oceanography and teaching“. There you can find many more exciting experiments, too!