In quantum mechanics, the electron is considered the fundamental unit of matter, as it is the smallest particle that carries an electric charge.

The energy bandgap in a semiconductor material is the energy difference between the valence band, which is the highest energy band that is filled with electrons, and the conduction band, which is the lowest energy band that is empty of electrons.

In a metal, electrical conduction primarily occurs due to the movement of free electrons, which are electrons that are not bound to any particular atom and can move freely throughout the material.

In an LED, light emission occurs through the process of electroluminescence, where the recombination of electrons and holes in a semiconductor material generates photons.

Solid solution strengthening is the primary mechanism for strengthening a metal alloy. It involves the addition of solute atoms to the solvent metal, which creates lattice distortions and hinders the movement of dislocations, resulting in increased strength.

Strength is the property of a material that describes its resistance to deformation under stress. It is measured by the amount of stress required to cause permanent deformation or failure in the material.

Resilience is the term used to describe the ability of a material to absorb energy without undergoing permanent deformation. It is measured by the amount of energy that can be stored in a material before it reaches its yield point.

In a solid material, heat transfer primarily occurs through conduction, which involves the transfer of heat energy from one atom or molecule to another through direct contact.

Hardness is the property of a material that describes its ability to resist wear and abrasion. It is measured by the resistance of a material to indentation or scratching.

In a photovoltaic cell, the generation of an electric current occurs through the photovoltaic effect, where the absorption of light energy by a semiconductor material creates an electron-hole pair, leading to the flow of current.

Plasticity is the term used to describe the ability of a material to undergo plastic deformation without fracture. It is characterized by the material's ability to retain its deformed shape after the removal of the applied stress.

In a fluid, heat transfer primarily occurs through convection, which involves the transfer of heat energy by the movement of the fluid itself.

Elasticity is the property of a material that describes its ability to store energy when deformed and release it upon unloading. It is characterized by the material's ability to return to its original shape after the removal of the applied stress.

In a laser, the emission of light occurs through the process of stimulated emission, where the interaction of an incident photon with an excited atom or molecule causes the emission of a second photon with the same energy and phase.

Opacity is the term used to describe the ability of a material to absorb and scatter electromagnetic radiation. It is the opposite of transparency.