What is Amorphous Solid?
An amorphous solid is that wherein the constituent particles don't have a customary three-dimensional course of action. Amorphous solids, without the three-dimensional long-range request of a glasslike material, have a more irregular game plan of particles, show short-range requests over a couple of atomic dimensions, and have physical properties very not quite the same as those of their comparing translucent states.
Amorphous solids look like liquids in that they don't have an arranged structure, an organized plan of atoms or ions in a three-dimensional structure. These solids don't have a sharp dissolving point and the solid to liquid transformation happens over a scope of temperatures. The physical properties displayed by amorphous solids are commonly isotropic as the properties don't rely upon the direction of estimation and show a similar extent in various directions.
This article, we will study what is amorphous solid, the difference between crystalline and amorphous solids, properties of amorphous solids, characteristics of amorphous solids, and what is an amorphous form.
Amorphous Solid Structure
Given below is an amorphous solid structure.
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Properties of Amorphous Solids
Amorphous solids are now and again portrayed as a supercooled liquid because their particles are organized arbitrarily fairly as in the liquid state.
Absence of Long - Range Order
Amorphous Solid doesn't have a long-range order of course of action of their constituent particles. Nonetheless, they may have little regions of the orderly plan. These translucent pieces of a generally amorphous solid are known as crystallites.
No Sharp Melting Point
An amorphous solid doesn't have a sharp melting point however melts over a scope of temperatures. For instance, glass on warming initially mellow and afterwards melts over a temperature range. Glass, consequently, can be formed or blown into different shapes. Amorphous solid doesn't have the trademark warmth of fusion.
Conversion Into a Glasslike Form
Amorphous solid, when warmed and afterwards cooled gradually by toughening, gets translucent at some temperature. That is the reason glass objects of antiquated time look smooth due to some crystallization having occurred.
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Difference between Crystalline and Amorphous Solid
Amorphous solids find numerous applications as a result of their remarkable properties. For instance, inorganic glasses discover applications in construction, houseware, research facilities, Rubber, another amorphous solid, is utilized in making tires, tubes, shoe soles and so on. Plastics are utilized broadly in family units and industry.
Examples of Amorphous Solids
Examples of amorphous solids are glasses, earthenware production, gels, polymers, quickly extinguished melts and slender film frameworks kept on a substrate at low temperatures. The investigation of amorphous materials is a functioning territory of examination. Notwithstanding tremendous advancement, as of late our comprehension of amorphous materials stays a long way from complete. The explanation is the nonappearance of the simplifications related to periodicity.
Regardless, from a correlation of the properties of materials in glasslike and an amorphous express, the fundamental highlights of the electronic structure and accordingly likewise perceptible properties are dictated by short-range order. Hence these properties are comparative for solids in the amorphous and glasslike state.
A few examples of amorphous solids are glass, elastic, pitch, numerous plastic and so forth Quartz is a case of a translucent solid which has standard order of the arrangement of SiO4 tetrahedra. On the off chance that quartz is melted and the melt is cooled quickly enough to evade crystallization an amorphous solid called glass is acquired.
Amorphous Solids are Isotropic
Amorphous solids are isotropic. That is, they display uniform properties every which way. The warm and electrical conductivities, coefficient of warm expansion and refractive file of an amorphous solid have a similar incentive in whatever direction the properties are estimated.
Some random translucent solid can be made amorphous by the quick cooling of its melt or by freezing its fumes. This doesn't permit the particles to arrange themselves in a glasslike pattern. At the point when quartz the glasslike form of SiO2 is melted and afterward quickly cooled, an amorphous solid known as quartz glass or silica glass results. This material has a similar composition SiO2 however comes up short on the sub-atomic level orderliness of quartz.
The amorphous form of metal alloys is acquired when slim movies of melted metal are quickly cooled. The subsequent metallic glasses are solid, adaptable and substantially more impervious to corrosion than the glasslike alloys of similar composition.
Different Types of Solids
Solids are divided into two categories depending on their essential structures. They can be crystalline solids or noncrystalline amorphous materials, depending on whether their structure is regular or disordered.
Almost every material may be rendered amorphous by rapidly cooling it from its liquid state, however certain materials are inherently amorphous because their constituent atoms or molecules cannot fit together in a regular manner. Other materials are amorphous because they have faults or impurities that prevent a stable lattice from forming.
The molecules or atoms in crystalline solids are organized in a repeating pattern called a lattice structure. A unit cell is the smallest repeating unit in that lattice arrangement. Solids of this sort are the most prevalent. They frequently split into flat faces and geometric forms when they crack.
Long-range order does not exist in amorphous solids. This implies that the pattern of atoms or molecules in one region of the solid will vary hugely from the pattern in another. Most amorphous solids, on the other hand, exhibit short-range order: At the molecular level, an image of a very small section of a solid may appear to be organized.
FAQs on Amorphous Solid
1. What is an amorphous solid as per the CBSE Class 12 Chemistry syllabus for the year 2025-26?
An amorphous solid is a substance whose constituent particles, such as atoms, ions, or molecules, do not possess a regular, repeating three-dimensional arrangement. Unlike crystalline solids, they lack a long-range order in their structure, causing them to behave more like supercooled liquids. This random arrangement of particles gives them unique properties.
2. What are the key differences between amorphous and crystalline solids?
The primary differences between amorphous and crystalline solids lie in their structure and resulting properties:
- Arrangement of Particles: Crystalline solids have a highly ordered, long-range repeating pattern (a crystal lattice), while amorphous solids have a disordered, random arrangement with only short-range order.
- Melting Point: Crystalline solids have a sharp, fixed melting point. Amorphous solids soften gradually over a range of temperatures.
- Cleavage Property: When cut, crystalline solids break into pieces with clean, flat surfaces. Amorphous solids break into irregular pieces with curved or uneven surfaces.
- Anisotropy vs. Isotropy: Crystalline solids are generally anisotropic (their physical properties vary with direction), whereas amorphous solids are isotropic, meaning their properties like refractive index and electrical conductivity are the same in all directions.
3. Why is glass considered an amorphous solid and not a crystalline solid?
Glass is considered an amorphous solid because its constituent particles (primarily SiO₄ tetrahedra) are not arranged in a regular, repeating lattice structure. It is formed by rapidly cooling molten silica, which prevents the molecules from having enough time to arrange themselves into an ordered crystalline pattern. As a result, the particles are frozen in a disordered, liquid-like arrangement, which is the defining characteristic of an amorphous state. This is also why glass is sometimes called a supercooled liquid.
4. What does it mean for an amorphous solid to be 'isotropic' in nature?
Isotropy means that the physical properties of a substance are uniform in all directions. Amorphous solids are isotropic because their constituent particles are arranged randomly and without a specific long-range order. Consequently, physical properties such as electrical conductivity, thermal expansion, and refractive index do not change regardless of the direction in which they are measured. This contrasts with anisotropic crystalline solids, where these properties can differ along different crystal axes.
5. Why do amorphous solids lack a sharp melting point?
Amorphous solids do not have a sharp melting point because of their irregular structure. In a crystalline solid, all bonds have similar strength due to the ordered arrangement, so they all break at a specific temperature. In an amorphous solid, the bonds between particles vary in strength and distance. When heated, the weaker bonds break first at lower temperatures, causing the solid to soften gradually. As the temperature increases, more bonds break until the entire material becomes liquid. This transition occurs over a range of temperatures rather than at one fixed point.
6. How can a crystalline solid like quartz be converted into an amorphous solid like quartz glass?
A crystalline solid can be transformed into an amorphous form through a process of rapid cooling, often called quenching. For example, when crystalline quartz (SiO₂) is melted at a high temperature, its ordered lattice structure breaks down. If this molten silica is then cooled very quickly, the atoms do not have sufficient time to rearrange themselves back into the ordered crystalline pattern. Instead, they are locked into a disordered, random arrangement, resulting in the formation of an amorphous solid known as quartz glass or silica glass.
7. What are five common examples of amorphous solids found in daily life?
Many everyday materials are amorphous solids. Five common examples include:
- Glass: Used in windows, bottles, and labware.
- Rubber: Used for making tires, shoe soles, and elastic bands.
- Plastics: Materials like polyethylene and PVC used in countless household and industrial products.
- Pitch/Tar: A black, viscous liquid that appears solid at room temperature.
- Polymers: Many synthetic polymers, like nylon and polystyrene, have an amorphous structure.
8. What are some important real-world applications of amorphous solids?
The unique properties of amorphous solids make them useful in various applications. For instance, amorphous silicon is used in photovoltaic cells to convert sunlight into electricity. Metallic glasses, which are amorphous metal alloys, are strong, flexible, and highly resistant to corrosion, making them suitable for specialised tools and electronic device casings. The ability of glass to be molded when soft allows it to be shaped into everything from complex laboratory equipment to artistic sculptures.
