If energy is removed from the liquid it finally reaches temperature where it freezes, that is - it converts to a solid. In molecular sense, the molecules become ordered. Another way to say this is that they form a lattice like framework. In solid state the molecules are found to have arranged themselves in orderly rows.
Solid state chemistry is the study of the synthesis, spatial and electronic structure, mechanical, thermal, electric, magnetic and optical properties and reactivities of solid substances.
DefinitionBack to Top
A solid interface is defined as a small number of atomic layers that separate two solids in intimate contact with one another, where the properties differ significantly from those of the bulk material it separates.
The discovery proved that X-rays were high frequency, short wavelength forms of electromagnetic radiation and that the resulting diffraction patterns could yield detailed information on solid state structures.
Solids are usually composed of atoms, molecules or ions arranged in a rigid, repeating geometric pattern of particles known as crystal lattice.
PropertiesBack to Top
The general properties of solids are listed below.
- Solids have a definite shape, mass and volume.
- Solids are almost incompressible, rigid and have mechanical strength.
- Solids have high density but very slow diffusion rate.
- Solids have close packed arrangements of atoms.
- Solids can only have vibrational motion as the constituents have fixed positions.
- Solid is the state of any matter in which constituents are firmly bound due to strong forces.
StructureBack to Top
The nature of arrangement of atoms or molecules in a material in large measure influences the degree of order and hence its crystallinity. Periodicity is related to the regular repetition of a representative unit of the structure along the directions in the crystal.The periodic atomic arrangement influences all of the properties.
There is a great diversity in the range of properties and applications of solids and an analysis of structure-property relations is fundamental to solid state chemistry. The structure of solids on at least three levels must be considered.
- The crystal structure of ideally perfect solids.
- The defect structure of solids, including the structure of surfaces.
- The texture of polycrystalline solids.
Sometimes a particular property is controlled entirely by one level of structure, for example the hardness of diamond relative to graphite is a consequence of its crystal structure. More often however the property depends on an interplay between the different levels of structure.
TypesBack to Top
Solids are divided into two types namely
- Crystalline solids
- Amorphous solids
- In crystalline solids the constituents are arranged in a definite or orderly manner which repeats itself over long distances.
- They are considered as true solids.
- Such solids have sharp melting points.
- They have definite geometry.
- They show clean cleavage along fixed cleavage planes.
- They show anisotropy, that is different physical properties in different directions due to orderly arrangements.
- Such solids do not have sharp melting points.
- These are considered pseudo solids.
- These shows isotropy, that is same physical properties in all directions due to irregular arrangements.
- They do not show clean cleavage. They have irregular cut.
- The constituents are not arranged in a regular or orderly manner over a long range.