Search results
Jan 29, 2020 · By Meredith Fore. A crystalline solid is a type of solid whose fundamental three-dimensional structure consists of a highly regular pattern of atoms or molecules, forming a crystal lattice. The majority of solids are crystalline solids, and the different arrangements of atoms and molecules within them can change their properties and appearance.
Mar 22, 2024 · A crystalline solid is a solid that consists of particles like atoms, ions, or molecules arranged consistently in a long range order. This pattern repeats throughout the solid, giving it a uniform structure. Most solid substances are crystalline. In these solids, the arrangement of particles maximizes the total force of attraction between them.
- Overview
- Classification
- Basic units of solids
- Long- and short-range order
- Categories of crystals
crystal, any solid material in which the component atoms are arranged in a definite pattern and whose surface regularity reflects its internal symmetry.
The definition of a solid appears obvious; a solid is generally thought of as being hard and firm. Upon inspection, however, the definition becomes less straightforward. A cube of butter, for example, is hard after being stored in a refrigerator and is clearly a solid. After remaining on the kitchen counter for a day, the same cube becomes quite so...
The basic units of solids are either atoms or atoms that have combined into molecules. The electrons of an atom move in orbits that form a shell structure around the nucleus. The shells are filled in a systematic order, with each shell accommodating only a small number of electrons. Different atoms have different numbers of electrons, which are distributed in a characteristic electronic structure of filled and partially filled shells. The arrangement of an atom’s electrons determines its chemical properties. The properties of solids are usually predictable from the properties of their constituent atoms and molecules, and the different shell structures of atoms are therefore responsible for the diversity of solids.
All occupied shells of the argon (Ar) atom, for example, are filled, resulting in a spherical atomic shape. In solid argon the atoms are arranged according to the closest packing of these spheres. The iron (Fe) atom, in contrast, has one electron shell that is only partially filled, giving the atom a net magnetic moment. Thus, crystalline iron is a magnet. The covalent bond between two carbon (C) atoms is the strongest bond found in nature. This strong bond is responsible for making diamond the hardest solid.
A solid is crystalline if it has long-range order. Once the positions of an atom and its neighbours are known at one point, the place of each atom is known precisely throughout the crystal. Most liquids lack long-range order, although many have short-range order. Short range is defined as the first- or second-nearest neighbours of an atom. In many liquids the first-neighbour atoms are arranged in the same structure as in the corresponding solid phase. At distances that are many atoms away, however, the positions of the atoms become uncorrelated. These fluids, such as water, have short-range order but lack long-range order. Certain liquids may have short-range order in one direction and long-range order in another direction; these special substances are called liquid crystals. Solid crystals have both short-range order and long-range order.
Solids that have short-range order but lack long-range order are called amorphous. Almost any material can be made amorphous by rapid solidification from the melt (molten state). This condition is unstable, and the solid will crystallize in time. If the timescale for crystallization is years, then the amorphous state appears stable. Glasses are an example of amorphous solids. In crystalline silicon (Si) each atom is tetrahedrally bonded to four neighbours. In amorphous silicon (a-Si) the same short-range order exists, but the bond directions become changed at distances farther away from any atom. Amorphous silicon is a type of glass. Quasicrystals are another type of solid that lack long-range order.
Students save 67%! Learn more about our special academic rate today.
Learn More
Crystals are classified in general categories, such as insulators, metals, semiconductors, and molecular solids. A single crystal of an insulator is usually transparent and resembles a piece of glass. Metals are shiny unless they have rusted. Semiconductors are sometimes shiny and sometimes transparent but are never rusty. Many crystals can be clas...
Mar 28, 2020 · Definition and Examples. Quartz crystals commonly occur in nature. (Ken Hammond, USDA) A crystal is a form of matter in which the atoms, molecules, or ions are arranged in a highly ordered three-dimensional lattice. Crystals are also called crystalline solids because most crystals are solid. However, liquid crystals also exist.
Oct 19, 2020 · Solids may be categorized as crystalline, polycrystalline, or amorphous. Crystalline Solid: Particles in a crystalline solid are arranged in a regular lattice. A good example is a salt crystal (sodium chloride). Polycrystalline Solid: In polycrystalline solids, tiny crystals called crystallites join together to form a larger structure. Many ...
A typical example of an "unconfined" phase transformation is the formation of snowflakes where the external boundaries of the solid have assumed crystalline appearance, reflecting in detail the internally ordered molecular (H2O) arrangement. Another unconfined formation of a solid is precipitation from solution (sugar crystals, CuSO4 and the like).
People also ask
What is a crystalline solid?
Why are crystals called crystalline solids?
Is a crystal a solid or a liquid?
What are the properties of crystalline solids?
Jun 29, 2017 · Summary. Some substances form crystalline solids consisting of particles in a very organized structure; others form amorphous (noncrystalline) solids with an internal structure that is not ordered. The main types of crystalline solids are ionic solids, metallic solids, covalent network solids, and molecular solids.
