We explain what the solid state is and what its main characteristics are. In addition, we explain the state changes it allows and more.
What is solid state?
Solid state is understood as one of the four essential forms of matter (along with liquid, gaseous and plasma), called aggregation states.
It is characterized by the rigidity of the bonds between its particleswhich gives it resistance to deformation and a very well-defined physical structure.
The particles of solid substances are joined together by forces of cohesion that maintain their stable shape and volume, and give them more or less hardness and resistance.
These forces, however, can be overcome through physical processes of change of state that allow a solid to be converted into a liquid or gas, or to turn naturally liquid or gaseous substances into solids.
See also: Metalloids
Solid State Characteristics
- Cohesion. The nature of solids is chemically identical to that of their liquid and gaseous variants, but in this state the particles that make up the matter are very close together, held in place by strong bonds (cohesive forces) that give the whole a defined shape. , with clear and coherent limits.
- Rigidity. Solids generally resist twisting and bending because they resist deformation. In other cases, they have shape memory: the tendency to maintain or recover their stable shape in the presence of deforming forces, such as weight or gravity.
- Incompressibility. Solids, unlike gases and liquids, cannot be compressed any more than they already are, so when subjected to extreme compression forces they often fracture or break down into smaller pieces. For this reason, a solid object cannot be placed in a container with a smaller volume than the solid object.
- HardnessMany solids are resistant to penetration by other solids, and even to having their surface scratched. This is known as hardness: physical resistance to other solids. The hardest known element is diamond.
- FragilityBrittleness often accompanies the hardness of solid materials, and is the ability of materials to crack, split, or break into smaller pieces when their resistance to deformation is exceeded by a specific force. It is the opposite of elasticity.
- Elasticity. Elasticity, contrary to fragility and hardness, is the property that some solids have of undergoing a momentary deformation in the presence of a constant force, and then returning to their original shape once released from it.
- Ductility. It is the property of some solids, especially some metals such as copper, to deform plastically in the presence of a sustained force, without breaking, forming threads or wires of the same material. Solids that have this capacity are ductile.
- Malleability. Malleable solids are those that can be shaped by deformation, that is, thin sheets of the material can be made without breaking. This property, along with ductility, is fundamental in the metals industry.
Processes of change to solid
There are physical processes to turn a substance that is not solid:
- SolidificationIt consists of removing heat energy from a specific liquid, slowing down the movement of its particles until they are forced to form firm bonds and acquire defined shapes, such as ice crystals.
- Freezing. It consists of compressing (increasing pressure) a liquid until its particles have more interaction and the transformation to a solid occurs.
- Deposition or reverse sublimation. It consists of modifying the temperature or pressure conditions of a gas, to make it crystallize or become a solid, without first passing through the liquid state.
Processes of change from solid to liquid and gas
Solids can become liquid or gas by modifying their temperature or pressure conditions in the following way:
- FusionIt is the increase in the temperature of a solid until it reaches its melting point. It is achieved by introducing energy to its particles and breaking the bond between them, which makes the solid flow towards liquidity.
- Sublimation. It is the opposite process to deposition, in which a solid is converted into a gas directly, by changes in its temperature and pressure, without first passing through the liquid state.
References:
- Introduction to Physics and Chemistry. 4th edition. Romilio Tambutti and Héctor Muñoz. 2005. ISBN: 968-18-5866-2
- Elasticity and resistance of materials I. Mariano Rodríguez-Avial Llardent and Antonio González-Alberto García. National University of Distance Education. 2020. ISBN: 978-84-362-6518-7
- General Physics Notes. José Pedro Agustín Valera Negrete. 2005. ISBN: 970-32-2987-5
- “Solid” in Wikipedia.