Radiation

Emission of Radiation.

 When Energy from some outside source is supplied to an electron, it absorbs a definite amount of energy and jumps to a higher energy state. Such a state of an atom in which the atom possesses more energy than possessed in the ground state is called the Excited State. This excited state is unstable and the electron tends to come back to the lower energy level. This transition (change) from upper to lower level occurs with a jump and energy is emitted in the form of a quantum equal to the difference in energies between the two levels. When this quantum of energy strikes the photographic plate it gives its impression in the form of a line. For example, if the electron comes back from energy level having energy E2  to energy level having energy E1, then the difference ( E2 – E1 ) may be expressed in terms of energy of photon as:      E2 – E1 = hv . Therefore, the frequency of the emitted radiation is given by,  v = E2 – E1 / h