The appearance of colour in solid alkali metal halides is generally due to :
- F-centres
- Schottky defect
- Frenkel defect
- interstitial positions
The Correct Option is A
Solution and Explanation
The appearance in colour in solid alkali metal halides is usually due to F− centres. When electrons occupy the vacant space of anions due to the presence of excess of metal ions, are called F-centres.
The Correct option is (A): F-centres.
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NEET Notification
Concepts Used:
Solid State
Solids are substances that are featured by a definite shape, volume, and high density. In the solid-state, the composed particles are arranged in several manners. Solid-state, in simple terms, means "no moving parts." Thus solid-state electronic devices are the ones inclusive of solid components that don’t change their position. Solid is a state of matter where the composed particles are arranged close to each other. The composed particles can be either atoms, molecules, or ions.
Types of Solids:
Based on the nature of the order that is present in the arrangement of their constituent particles solids can be divided into two types;
- Amorphous solids behave the same as super cool liquids due to the arrangement of constituent particles in short-range order. They are isotropic and have a broad melting point (range is about greater than 5°C).
- Crystalline solids have a fixed shape and the constituent particles are arranged in a long-range order.