We explain what matter is in physics and what its characteristics are. Also, the states it presents and its structure.
What is matter (physics)?
According to the physics approach, matter refers to any entity endowed with its own mass and capable of occupying a space at a given time. All physical objects are composed of matter, from a car to an atom and the elementary particles that compose it.
The notion of matter within the field of physics has been defined and redefined over the centuries, from ancient times (when the notion of atoms arose), to the times of Isaac Newton and then Albert Einstein. The discovery of subatomic matter and the inauguration of particle physics has been the most revolutionary event in the field when it comes to thinking about matter.
Therefore, the initial definition of matter that we gave was sufficient for the classical branches of physics, but it is problematic within the field of quantum mechanics, where the notions of “mass” and “space” are much more complicated.
See also: General properties of matter
Characteristics of matter in physics
Matter has certain specific properties, such as mass and volume, that is, matter occupies a certain region in space-time. This means that the matter It has measurable properties, such as proportions (length, width, height) density, weight, hardness, fluidity, malleability, among many others. To know matter is to understand precisely its physical properties, radically different from those of, for example, energy.
On the other hand, the matter must be in one of the known states or phases according to the distribution, grouping and properties of its particles. Thus, matter occurs in a solid, liquid and gaseous state, although, under certain extreme conditions of pressure and temperature, it can also be found in a plasmatic state (ionized gaseous). There are other more complex states of matter that are studied in advanced fields of physics and that are unstable.
In addition to matter, there is antimatter, which can be understood as matter composed of antiparticles. For every elementary particle that exists, there is another identical one but with an opposite electrical charge, which causes the annihilation of both when they interact.
States of matter
There are three main states of matter, according to physics: solid, liquid and gas, although there are also other less frequent states, such as plasma or fermionic condensates, reproducible only in the laboratory. Each physical state has different characteristics that have a lot to do with how the particles of the system under study are arranged in space and the energy they have.
- Solid The particles of solid matter are very, very close together, prey to very intense forces of attraction. For this reason, they behave as a single body, with great cohesion, density and a constant shape. They present resistance to fragmentation and have low or no fluidity: they cannot be compressed and, when they are broken or fragmented, other smaller solids are obtained from them.
- Liquids The particles of liquid matter are held together by forces of attraction, much weaker and less ordered than those of solids. For this reason, liquids lack a fixed and stable shape, as well as cohesion and resistance, which is why they take on the shape of the container that contains them. They have great fluidity (they can be introduced into small spaces) and a surface tension that makes them adhere to surfaces, they are poorly compressible and, with the exception of water, they usually contract in the presence of cold.
- Gases The particles of gaseous matter are in such a state of dispersion and separation that they barely manage to stay together at all: the force of attraction between them is weak, which causes a state of disorder between them. Since they cannot come together and form a massive compact body, gravity has no appreciable effect on them. They occupy a much larger volume than liquids and solids, since they tend to expand until they occupy the entire space that contains them. They lack a fixed shape and volume and are sometimes colorless and/or odorless.
Matter can be transformed from one state to another just by altering the temperature and pressure conditions at which it is located. Its chemical properties, however, will remain the same.
structure of matter
All known matter is composed of microscopic units called atoms formed, in turn, by three subatomic particles:
- Electrons Equipped with a negative charge and small size, these particles orbit the nucleus of the atom in a set of trajectories called orbitals, with a greater or lesser amount of energy according to their proximity or distance from the nucleus.
- Protons Endowed with a positive charge and larger in size, they are found in the nucleus of the atom, and constitute the main part of its mass and weight.
- Neutrons Without any electrical charge, they are found in the nucleus of the atom along with the protons, providing mass and weight to the atom although it does not influence its electromagnetism.
Depending on the number of electrons, protons and neutrons that an atom has, it will make up the known chemical elements categorized in the Periodic Table. For example, the simplest atom that exists is hydrogen, which has only one electron and one proton.
References
- “Matter (physics)” on Wikipedia.
- “Internal structure of matter” (video) in Private Professor Puebla.
- “States of matter” in ICT Resources.
- “Structure of matter” in Wikibooks.
