Difference Between Amorphous Solids and Crystalline Solids

Main Difference

Solid is one of a state of matter, the other two being liquid and gas. A solid material has a proper shape, volume, and size. Further solids are classified in many types. One of the major types of solid is amorphous solid, in this type of solid the atoms or molecules are not arranged in a definite pattern. It is a noncrystalline solid that has atoms near each other. It’s common examples are glass, plastic, etc. Another type of solid is crystalline solid; it is a type of a solid whose atoms or molecules are arranged in a highly organized order forming a crystal lattice in all the possible directions. It also has atoms near each other. It’s common examples are crystals of NaCl etc. So the conclusion is that the main difference in amorphous and crystalline solids is of structure and arrangement of atoms and molecules.

Comparison Chart

BasisAmorphous SolidsCrystalline Solids
Geometry StructureAmorphous solids have an irregular geometry or structure.Crystalline solids have a regular geometry or structure.
ArrangementAmorphous solids have atoms arrangement in an indefinite manner.Crystalline solids have atoms arrangement in a definite manner.
Intermolecular ForcesAmorphous solids have non-uniform intermolecular forces.Crystalline solids have uniform intermolecular forces between them.
Melting & BoilingAmorphous solids do not have a sharp melting or boiling point.Crystalline solids have sharp melting and boiling point
RigidLess rigid.More rigid.
PropertiesAmorphous solids show isotropic properties.Crystalline solids show anisotropic properties.

What are Amorphous Solids?

Amorphous solid is one of the major categories of solids. Amorphous solid is defined as a solid that have an irregular or indefinite arrangement of atoms and molecules in it. In this, all the atoms are closely packed and are at a very closer proximity with each other. Amorphous solids are isotropic in properties and independent of direction. In this solid, the distance and direction of the units of atoms vary from one another as it is irregular. It gradually gets soft at a high temperature, and if it is maintained there for a longer period, the atoms start to arrange them self in a regular manner as in crystalline solids. One thing to be noted that amorphous solid don’t have a definite melting point. When amorphous solids are broken or cleaved, they produce irregular fragments. They also show a poor or indefinite patterns when exposed to x-rays due to their irregular structure. Amorphous solids are less rigid than crystalline solids. The prominent examples of amorphous solids are fiberglass, plastics, Teflon, etc.

What are Crystalline solids?

The crystalline solid is one of the major categories of solids. The crystalline solid is defined as a solid that have a regular or definite arrangement of atoms and molecules in it. In this, all the atoms are closely packed and are at a very closer proximity with each other. Intermolecular forces holding them are uniform. Crystalline solids are anisotropic in properties and dependent of direction. In this solid, the distance and direction of the units of atoms don’t vary from one another as it is regular. They melt at their melting point. One thing to be noted that crystalline solid has a definite melting point. They show a good or define patterns when exposed to x-rays due to their regular structure. Crystalline solids are more rigid than amorphous solids. For example, crystals of NaCl, etc.

Key Differences

  1. Amorphous solids have an irregular geometry or structure while crystalline solids have a regular geometry or structure.
  2. Amorphous solids have atoms arrangement in an indefinite manner, whereas crystalline solids have atoms arrangement in a definite manner.
  3. Amorphous solids give poor pattern when exposed to x-rays while crystalline solids give a good and definite pattern.
  4. Amorphous solids have non-uniform intermolecular forces while crystalline solids have uniform intermolecular forces between them.
  5. Amorphous solids do not have a sharp melting or boiling point, but crystalline solids have sharp melting and boiling point.
  6. Amorphous solids are less rigid while crystalline solids are more rigid.
  7. Amorphous solids show isotropic properties, whereas crystalline solids show anisotropic properties.

Comparison Video

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Harlon Moss

Harlon currently works as a quality moderator and content writer for Difference Wiki. He graduated from the University of California in 2010 with a degree in Computer Science. Follow him on Twitter @HarlonMoss

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