1 Common rashes include eczema, poison ivy, hives, and athlete's foot. 2  Infections that cause rashes may be fungal, bacterial, parasitic, or viral.  Over-the-counter products may be helpful treatments for many skin rashes.
The conditions under which this process occurs happen in two ways. According to the Cornell Center for... Atoms emit a photon when an electron falls from a high-energy state to a low-energy state. The conditions under which this process occurs happen in two ways. According to the Cornell Center for...
Photon {foh'-tahn}. A photon is a quantum of light, or the smallest possible packet of light at a given wavelength. It is emitted by an atom during a transition from one energy state to another. As FUNDAMENTAL PARTICLES, photons travel at the speed of light and have mass and momentum dependent on their frequencies.