Guwahati, March 2 -- Courtney Di Vittorio, Wake Forest University

Curious Kids is a series for children of all ages. If you have a question you'd like an expert to answer, send it to curiouskidsus@theconversation.com.

What do you picture when you think of water? An icy, refreshing drink? A crystal-blue ocean stretching to the horizon? A lake reflecting majestic mountains? Or a small pond that looks dark and murky?

You would probably be more excited to swim in some of these waters than in others. And the ones that seem cleanest would probably be the most appealing. Whether or not you realize it, you are applying concepts in physics, biology and chemistry to decide whether you should leap in.

The color of water offers information about ...