Density applies to many if not all aspects of life. With density you can explain why ice floats. You can explain why oxygen is on the earth, and not floating around in space( or being replaced by another gas). You can also explain why heat rises while cold air sinks.
Answer:
The formation of a rainbow is more a demonstration of the wave-like behavior of light.
Explanation:
A rainbow is caused by the interaction of sunlight with atmospheric conditions. A rainbow formation results from the refraction and reflection of light due to changes in the light's wavelength direction. Naturally, light enters a water droplet, slowing down and bending as it goes from air to denser water in a refraction as if "bent." Then light reflects off the inside of the droplet, separating into its component wavelengths or colors. With light exiting from the droplet, a rainbow is formed.
From that particular list:
Mica (A), Quartz (B), and Copper (D) are minerals.
Steam (C) isn't.