Unusual breath odors are common in kids. Typically there isnât anything to worry about, but there are some breath odors that indicate an underlying problem. In children smelly breath that persists throughout the day is most often the result of mouth-breathing, which dries out the mouth and allows the bacteria to grow.
Light is composed of particles called photons, and matter is composed of particles called electrons, protons, neutrons. It's only when the mass of a particle gets small enough that its wavelike properties show up. To help understand all this let's look at how light behaves as a wave and as a particle.
This aspect of the discussion suggests that light and other electromagnetic radiation are waves. It was very disturbing, therefore, when phenomena were discovered (around 1900) that clearly indicated that light was made up of particles called photons. One such phenomenon involved the photoelectric effect. It was known that if one shines a beam of light on a clean surface of a metal, electrons will be ejected from the metal. The light has to exceed a certain energy, to remove electrons from the metal surface.