Crystalline and Amorphous Solids: Properties, Structures, and Examples, Lecture notes of Chemistry

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Solids and their

Properties

• ajg

Salt

Gemstones

Alum

Plastic

Chocolate Bar

Solids can be categorized into two groups:

• crystalline solids
• amorphous solids

The differences in properties of these

two groups of solids arise from the presence or

absence of long-range order of arrangements

of the particles in the solid.

Solids can be categorized into two groups:

a. CRYSTALLINE SOLID

• Crystalline solids are arranged in fixed geometric patterns or lattices. Examples:
• ice
• sodium chloride (NaCl)
• copper sulfate (CuSO 4 )
• Diamond
• Graphite
• sugar (C 12 H 22 O 11 ) The ordered arrangement of their units maximizes the space they occupy and are essentially incompressible.

CRYSTALLINE SOLID

• ICE NaCl CuSO

The Crystal Lattice

Crystalline solids are characterized by

a regular repeating structure called

the crystal lattice

X-ray Diffraction is a technique used to determine the atomic and molecular structure of a crystal, wherein atoms cause a beams of incident X-rays to diffract into many specific directions. A stream of X-rays directed at a crystal diffracts and scatters as it encounters atoms. The scattered rays interfere with each other and produce a pattern of spots of different intensities that can be recorded on film. X-ray Diffraction An X-ray diffraction pattern of a graphite crystal.

There are two main methods for obtaining salt, evaporation from sea water and mining salt from the earth. Most common table salts and salts used for industrial purposes are obtained through mining, while specialty or gourmet salts are still produced via evaporation of sea water.