Which is an example of a chemical change? A pot of water boiling and turning into water vapor
Iron wheels of roller skates rusting when it rains outside
Water in a nice cube tray freezing into ice
Ripping up a piece of paper

What is the thinnest soap film (excluding the case of zero thickness) that appears black when illuminated with light with a wavelength of 480 ? the index of refraction of the film is 1.34, and there is air on both sides of the film. express your answer in nanometers. hint 1. how to approach th