What is the matter?

We explain what matter is and what its chemical and physical properties are. In addition, how it is classified and some examples of matter.

1. What is the matter?

We call matter to everything that occupies a certain place in the universe , has a certain amount of energy and is subject to interactions and changes over time , which can be measured. From a chemical point of view , matter is the set of constituent elements of perceivable reality , that is, what constitutes the things around us and ourselves.

We use the term matter as a synonym for substance , that is, the thing from which objects are made , and we understand it scientifically as a different kind of phenomenon from that of forces or energies: the dynamics that interact with objects.

Matter is found everywhere , and in any physical state. There is matter in the air that is breathed as well as in a glass of water . Everything we see, feel and touch is matter, which is a fundamental element for the development of life on the planet .

As far as we know, matter is made up of invisible, indivisible and stable particles , which we call atoms . There are 118 types of atoms, that is, of chemical elements or pure substances , indivisible in simpler ones, reflected in the Periodic Table of the Elements. These atoms are different from each other, depending on the quantity or distribution of subatomic particles , which are always of three types: electrons (negative charge), protons (positive charge) and neutrons (neutral charge).

The reactions between the forms of matter are known as chemical reactions.

2. Chemical properties of matter

Every form of matter reacts in the presence of other related substances, according to certain constitutive properties of its atoms or molecules , which allows the result of these reactions to be substances different from the initial ones (more complex or simpler).

Among the main chemical properties of matter are:

• PH . The corrosivity of acids and the causticity of the bases has to do with the pH of the matter, that is, its level of acidity or alkalinity, its ability to donate or receive electrons when in contact with certain materials, such as metals or as the organic matter . These reactions are usually exothermic, that is, they generate heat.
• Reactivity According to its atomic constitution, matter can be more or less reactive, that is, more or less prone to combine with other substances. In the case of the most reactive forms, such as cesium (Ce) and francium (Fr) metals, it is rare to see them in pure forms, they are almost always part of compounds with other elements. The so-called noble gases or inert gases, on the other hand, are forms of matter with very low reactivity, which have almost no reaction with any other substance.
• Inflammability. Some substances may ignite, that is, generate an explosion of heat that leads to flames, in the presence of a heat source or in reaction with other substances. This material is called flammable, such as gasoline.
• Radioactivity Not all atoms of matter are stable. Some acquire unstable forms that release particles or waves of energy, in the form of ionizing radiation, highly dangerous for life. This is radioactivity, and is typical of some elements or some atoms resulting from artificial reactions such as fission and atomic fusion. Once they release their excess energy , radioactive atoms degenerate into a different, more stable element.

3. Physical properties of matter

Matter also has physical properties, that is, properties derived from changes in its appearance, without altering its chemical essence and linked to the action of other external natural forces.

Among the main physical properties of matter are:

• Temperature . The degree of heat that matter presents at a time, which generally radiates towards the environment when there is a considerable temperature difference, as occurs with hot water left at rest. Temperature is the degree of kinetic energy that the particles of a material present.
• State of aggregation . Matter can appear in three “states” or molecular structures determined by its temperature or the pressure to which it is subjected. These three states are: solid (particles very close together, low kinetic energy), liquid (particles less together, enough kinetic energy for matter to flow, without separating at all) and gas (particles far apart, high kinetic energy).
• Conductibility . There are two forms of conductivity: thermal ( heat ) and electrical ( electromagnetism ), and in both cases it is the ability of materials to allow the transit of energy through their particles. High conductivity materials are known as conductors, those with low conductivity as semiconductors and those with no conductivity as insulators.
• Melting point . It is the degree of temperature at which a solid can change state of aggregation and become liquid.
• Boiling point . It is the degree of temperature at which a liquid can change state of aggregation and become gaseous.

4. Classification of the subject

There are many ways and criteria to classify the subject. From a general point of view, we can list the main ones as follows:

• Living matter. Conforms living beings while they are alive.
• Inanimate matter . Make up inert, lifeless, or dead objects.
• Organic matter . That formed mainly by atoms of carbon and hydrogen, and that is generally linked to the chemistry of life.
• Inorganic matter . It is not organic, that is, that it is free in nature and does not necessarily have to do with life, but with spontaneous chemical reactions such as electromagnetism.
• Simple matter.  It is composed of atoms of few different types, that is, that is closer to purity.
• Composite matter It consists of numerous elements of different types, reaching high levels of complexity.

5. Subject Examples

Virtually all objects in the universe are a good example of matter , while they are formed by atoms and possess determinable, discernible and measurable physicochemical properties.

Stones, metals , the air we breathe, wood, our bodies, the water we drink, all the objects we use every day, are perfect examples of matter. There are even recent theories of quantum physics that propose that the void, understood so far as the absence of matter, would also be “filled” with some kind of particles, called “Higgs bosons.”