Characteristics of Solids


  • Solids are densely packed formations that cannot be easily influenced by external factors.

  • They have a set volume, mass and form as well. However, solids never flow. The chemical and physical properties of solids are studied in solid-state chemistry & solid-state physics.

  • Nature has four different states of matter. Based on their intermolecular interaction as well as the nature of the component particles, they are classed as solids, gases, liquids & plasma.

Solid-liquid-gas.jpg: Sadi Carnot derivative work: Dave.Dunford (talk) 13:43, 15 December 2010 (UTC), Solid-liquid-gas, marked as public domain, more details on Wikimedia Commons

What is a Solid State?

  • Solids are one of the 3 forms of matter that have a firmly packed structure and a set volume and structure.

  • Chemical bonding, which keeps the molecules together, is responsible for the hard structure because the molecules are firmly bonded, their kinetic energy is smaller than those of gases and liquids.

  • This property allows them to resist the activities of external factors and therefore maintain a constant volume and form, as opposed to gases and liquids which are very volatile.

Characteristics Of Solids

  • Because significant intermolecular interactions keep the component particles of matter together, solids have a particular weight, volume, and form. At low temperatures, the intermolecular force tends to control heat energy, and solids remain in a stable state. The volume and mass of a liquid and a solid state are the same for a given substance.

  • Conductivity, density, and optical transmission are just a few of the numerous characteristics of solids.

  • Common table salt, water ice, dry ice, rock, most metals, & wood are instances of solids. The atoms or molecules in a solid gain kinetic energy when warmed.

  • There are 2 types of solids: crystalline & amorphous. The most frequent form of solid is crystalline solid. They are distinguished by a consistent crystalline arrangement of atoms that confers long-range order. This long-range organization is absent in non-crystalline or amorphous substances. Crystalline solids are those that have their atoms, ions, or molecules arranged in a regular, well-defined pattern.

  • Molecular, Ionic, covalent, and metallic solids are the four primary kinds of solids. Ionic solids are made up of ions with positive and negative charges that are bound together by electrostatic interaction; the bonding strength is represented in the lattice energy. Ionic solids have a high melting point and are quite hard.

  • Some chemicals create crystalline solids, which are composed of particles in a highly structured manner; others form amorphous solids, which have an unorganized inner structure.

  • Mechanical properties of solids explain properties such as deformation and strength resistance. Plasticity, abrasion, ductility, malleability, and toughness are examples of mechanical qualities.

  • A solid is distinguished by its structural stiffness & resistance to force applied to its surface. A solid substance, unlike a liquid, does not move to take on the shape of its vessel, nor does it swell to fill the full available capacity as gas does.

  • Solids have distinct forms & dimensions and are not compressible in any way.

  • The ions, atoms, or molecules in crystalline materials are organized in an organized & symmetrical arrangement that is repeated throughout the crystal. A unit cell represents the smallest recurring structure of a solid, similar to a brick in a wall. A crystal lattice is a network formed by unit cells.


Solid-state materials are widely used everywhere around us. Among the most important are −

  • Mobile phones and personal computers are examples of electronic devices.

  • Lasers and fibre optics are examples of optical devices.

As a result, the entire concept of modern invention is based on solid-state physics concepts.


  • Commonplace items like wiring in a building and window panes, as well as the magnet in a fridge, are heavily reliant on solid-state.

  • Logic and memory bits are made of silicon, which is solid.


It can be concluded that solids, which have a tightly packed structure, are one of the 4 states of matter. Solids are defined by their volume and form. Solids cannot flow because they are incompressible. Strong intermolecular interactions hold constituent particles together in solids. Based on the organization of component particles, solids are classified as crystalline/amorphous. Crystalline solids feature regular geometric forms, anisotropic melting temperatures, and sharp edges. They have distinct heat of fusion and cleavage characteristics. Amorphous materials are disordered pseudo or supercooled liquids. They have no cleavage characteristics and are isotropic. They soften across a greater temperature range and may crystallize when warmed.


Q1. Why is sugar stiffer than air and water?

Ans. Sugar is a crystalline solid with tightly packed component molecules in a 3D space.

In this three-dimensional region, they are bound together tightly by strong intermolecular forces acting in predictable patterns across a long distance. This limits the mobility of these molecules, allowing them to oscillate solely over a mean location. In liquid and gas on the other hand molecules are kept together by moderate and weak intermolecular forces. As a result, they have kinetic energy and may move. As a result, they are less stiff than sugar.

Q2. Glass is a kind of solid. Why is it referred to as a supercooled liquid?

Ans. Glasses are amorphous solids since they lack a distinct shape and are composed of molecules held together by comparably weaker forces. Though they feature regular recurring patterns, they can only be seen from a limited distance. As a result, the particle structure becomes exceedingly disorderly. Because of the chaotic arrangement of component particles, they are referred to as pseudo solids or supercooled liquids.

Q3. Why is graphite a better conductor of electricity than a diamond?

Ans. To carry electricity, a compound must include free or delocalized electrons. Each carbon atom in graphite is linked to three other carbon atoms nearby. This frees up the fourth electron for movement. Diamond, on the other hand, does not contain free electrons due to their tetrahedral structure formed by strong covalent bonding. In comparison to diamond, which has no free electrons, graphite conducts electricity due to these free electrons.

Q4. Is plastic an isotropic material?

Ans. Isotropic materials have qualities that do not vary when tested in different orientations. Plastic is an amorphous solid, and its properties do not alter in various directions due to the disorderly arrangement of component particles. It is extremely malleable and can take on any shape. Because its elements' qualities are the same in every orientation, its behaviour, is likewise extremely predictable. All of these characteristics combine to make it isotropic.

Q5. Why is graphite more brittle than a diamond?

Ans. Diamond and graphite are both carbon compounds. The nature of the component particle bonding distinguishes them. Carbon atoms are bound together tightly in a lattice structure within a diamond by strong covalent bonds. Each carbon in this tetrahedral structure is connected to 4 others, and there are no free electrons. As a result, diamonds are tougher. In graphite, free electrons are formed by the connection of carbon atoms. Each carbon is connected to just three others nearby. Graphite is more brittle than diamond due to its characteristics.

Updated on: 18-Apr-2023


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