DENDROLOGY

Detailed explanation-1: -An electron can become excited if it is given extra energy, such as if it absorbs a photon, or packet of light, or collides with a nearby atom or particle.

Detailed explanation-2: -Two gold ions (Au) moving in opposite directions close to the speed of light (v≈c) are each surrounded by a cloud of real photons (). When these photons collide, they create a matter-antimatter pair: an electron (e-) and positron (e+).

Detailed explanation-3: -The amount of energy is directly proportional to the photon’s electromagnetic frequency and thus, equivalently, is inversely proportional to the wavelength. The higher the photon’s frequency, the higher its energy. Equivalently, the longer the photon’s wavelength, the lower its energy.

Detailed explanation-4: -When photons of light hit a metal surface, electrons are sometimes emitted from the metal’s atoms. Light also travels in waves. In fact, the energy of the emitted electrons depends on the wavelength of light that hits the metal. The shorter the wavelength, the more energy these emitted electrons have.