Heat transfer through radiation takes place in form of electromagnetic waves mainly in the infrared region. The radiation energy per unit time from a black body is proportional to the fourth power of the absolute temperature and can be expressed with Stefan-Boltzmann Law as.The radiation transfers energy and also momentum. It travels through a vacuum at the speed of light, c , which is a fundamental constant equal to about 3 × 10 5 km s –1. The speed is slightly reduced on entering a medium, such as air or glass. Electromagnetic radiation is caused by the acceleration of charged particles, such as electrons.
The energy of an electron depends on the size of the orbit and is lower for smaller orbits. Radiation can occur only when the electron jumps from one orbit to another. The atom will be completely stable in the state with the smallest orbit, since there is no orbit of lower energy into which the electron can jump.
Dec 19, 2020 · Use the Periodic Table to determine the energy level and sublevel of the highest energy electrons in each of the following elements: (a) N (b) Ca (c) Rb (d) P (e) In; Decide whether each of the following statements is true or false. (a) Li has valence electrons in the n = 1 energy level. (b) Si has valence electrons in the n = 3 energy level.