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

What is matter?

We call matter everything that occupies a certain place in the universe or space, has a certain amount of energy and is subject to interactions and changes over time, which can be measured with some measuring instrument.

From a chemical point of view, matter is the set of constituent elements of perceptible reality, that is, what constitutes the substances around us and ourselves. Chemistry is the science that deals with studying the composition and transformation of matter.

We use the term matter as a synonym of substancethat is, the thing from which the objects are made and we understand it scientifically as something different from forces or energies, which are more related to the dynamics that interact with objects.

The matter is found everywhere and in any physical state (solid, liquid, gas, plasma). There is matter in the air you breathe, as well as in a glass of water. Everything we see, feel and touch is matter, and that is why it is fundamental for the development of life on the planet.

As far as we know, chemically matter It is made up of microscopic particles which we call atoms. Atoms constitute the fundamental units of matter. Each atom has the properties of the chemical element to which it belongs. There are so far 118 chemical elements that are located, ordered and classified in the Periodic Table of the elements.

On the other hand, atoms are different from each other, depending on the quantity or distribution of their subatomic particles, which are always of three types: electrons (negative charge), protons (positive charge) and neutrons (neutral charge). The protons and neutrons are in the atomic nucleus, and the electrons around it.

Reactions between forms of matter or different substances are known as chemical reactions.

They may help you: Origin of matter

Chemical properties of matter

Every form of matter reacts in the presence of other 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 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 it is in contact with certain materials, such as metals or like organic matter. These reactions are usually exothermic, that is, they generate heat. On the other hand, pH measures the amount of H ions₃EITHER⁺ or OH^– of a substance or a solution.
• 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 the metals cesium (Ce) and francium (Fr), 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 almost do not react with any other substance.
• Inflammability Some substances can ignite, that is, generate an explosion that releases heat and produces flames, in the presence of a heat source or in a reaction with other substances. Such matter is called flammable (for example, gasoline).
• Oxidation It is the loss of electrons from an atom or ion when it reacts with a certain compound.
• Reduction. It is the gain of electrons of an atom or ion when it reacts to a certain compound.

Physical properties of matter

Matter also has physical properties, that is, properties derived from changes in its appearance that are linked to the action of other external forces. Physical properties are not related to the chemical composition of substances.

Among the main physical properties of matter are:

• Temperature It is the degree of heat that matter presents at a moment, which generally radiates towards the environment when a substance has a higher temperature than its environment. Temperature is the degree of kinetic energy that the particles of a material have.
• Aggregation status. 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 close together, enough kinetic energy for the matter to flow, without completely separating) and gaseous (particles very far apart, high kinetic energy).
• Conductivity or conductivity There are two forms of conductivity: thermal (heat) and electrical (electromagnetism), and in both cases it is the ability of materials to allow energy to pass through their particles. Materials with high conductivity are known as conductors, those with low conductivity as semiconductors, and those with zero conductivity as insulators.
• Melting point It is the temperature at which a solid transforms into a liquid at a pressure of 1 atm.
• Boiling point. It is the temperature at which the vapor pressure of a liquid becomes equal to the pressure that exists around the liquid. At this point the liquid transforms into vapor. When the vapor pressure of the liquid is equal to the atmospheric pressure it is called “Normal boiling point”.

Classification of matter

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

• Living matter It shapes living beings, while they are alive.
• inanimate matter. It makes up inert, lifeless, or dead objects.
• organic matter. Made up mainly of carbon and hydrogen atoms, and is generally linked to the chemistry of life.
• Inorganic matter. It is not organic and does not necessarily have to do with life but with spontaneous or non-spontaneous chemical reactions.
• Simple matter. It is composed of atoms of a few different types, that is, it is closer to purity.
• Composite matter. It is made up of numerous elements of various types, reaching high levels of complexity.

Examples of matter

Practically all objects in the universe are a good example of matter as long as they are made up of atoms and have determinable, discernible and measurable physical-chemical properties.

The stones, the metals, the air we breathe, the wood, our bodies the water we drink, all the objects we use daily are perfect examples of matter. There are even recent theories of quantum physics that propose that the vacuum, understood until now as the absence of matter, would also be “filled” with some type of particles, called “Higgs bosons.”

Continue with: Levels of organization of matter

References

• “Matter” in Wikipedia.
• “Matter and its properties” (video) Happy Learning Spanish.
• “What is matter?” (video) on Profesapp.
• “States of matter” (video) in Educatina.
• “Matter” in The Encyclopaedia Britannica.