Question

Define f-centers mention the consequences of f-centers

Answer 1

An F-center, Farbe center or color center (from the original German Farbzentrum; Farbe means color, and zentrum center) is a type of crystallographic defect in which an anionic vacancy in a crystal is filled by one or more unpaired electrons.

Answer 2

Answer:

F-Centers are the anionic sites occupied by unpaired electrons. They impart colour to crystals. This colour is due to excitation of the electrons when they absorb energy from the visible light.

F-centres are formed by heating alkyl halide with excess of alkali metal.

Examples: NaCl crystals heated in presence of Na-vapor yellow color is produced due to f-centres.