Question

Why does the presence of excess of lithium makes licl crystals pink? a solid with cubic crystal is made of elements p & q. atoms of q are at the corners and p is at the body centres in cube. find formula of crystal?

Answer 1

When a crystal of LiCl is heated in an atmosphere of Li vapour, the Li atoms lose electron to form Li+ ions. The released electrons diffuse into the crystal and occupy anionic sites (F-centres). These electrons impart pink colour to the LiCl crystal..

LiCl is facecentred cubic lattice...resembling rocksalt(NaCl)...which is made up of Li+ and Cl- ions.

A negative ion might be missing from its lattice site and leaves a hole, which is occupied by an electron and hence maintaining an electrical balance. The trapped electrons are termed as F-centers or color centers as they are responsible for giving color to the crystal.

Answer 2

Explanation:

hope it will help you...