PROPERTIES OF MATTER (PHYSICAL AND CHEMICAL) - SCIENCE - 2025

The properties of matter can be classified into general and specific. General ones are those that are common to all physical bodies or entities, such as: mass, volume, porosity, impenetrability, inertia, divisibility, etc.

Meanwhile, the specific properties of matter are constituted by the set of characteristics that allow to establish differences between substances, as well as their identification.

Specific properties are classified into physical properties and chemical properties; that is, they are the ones that allow the characterization of a compound to highlight its identity with respect to another.

Thanks to these properties, certain patterns of reactivity can also be established in the different blocks of the periodic table; how they interact with each other, with their environment, heat or with radiation of different wavelengths.

Matter due to its existence has a set of properties; for example, it has a mass and occupies a spatial place. Etymologically matter has by definition: "the substance from which things are made", and in the case of chemistry, it refers to its atoms or molecules.

Physical properties of matter

The physical properties of the stones do not imply any change in their composition, since they are considered as a whole, while the chemical properties specify more of what they are made of and the reactions they may undergo. Source: Pixabay.

It is the set of properties of matter that can be measured or evidenced without a change or alteration of its internal composition, at the molecular or atomic level. Physical properties are classified into extensive properties and intensive properties.

- Extensive

As its name indicates, they are the physical properties that depend on the extent and amount of matter being considered. Among the extensive properties are the following: mass, volume, weight, pressure, inertia, kinetic energy, potential energy, length, etc.

Mass

It is the amount of matter in a body that does not depend on the position of the body on the earth's surface. The most massive regions of the universe are black holes.

Volume

It is the extension of the space occupied by a body.

Weight

It is the force exerted on a mass due to the existence of the acceleration of gravity (9.8 m / s ²). The weight of a body will be greater on the surface of the Earth than inside an airplane in flight; while the mass does not vary with its spatial location.

Pressure

It is the force exerted by a gas or a liquid per unit area of ​​the container that contains it.

Inertia

In the absence of an external force, a body tends to remain at rest or to move at a constant speed, that is, with the absence of acceleration.

Kinetic energy

It is the amount of energy in a body due to the speed of its movement. It is an extensive property because it depends on the mass of the body.

Potential energy

It is the energy of a body due to its spatial position; for example, how high you are.

Length

It is the extension of a body in a single dimension of space.

- Intensive

It is the set of properties that do not depend on the amount of matter that is being considered. Therefore, it can be said that they are inherent properties of matter and serve to identify substances and characterize them.

Among the intrinsic properties are the following: physical appearance, color, odor, taste, melting point, boiling point, sublimation, solubility, hardness, viscosity, surface tension, electrical conductivity, thermal conductivity, malleability, ductility, decomposition, toxicity, etc.

Physical appearance

It understands the physical state of matter, indicating whether it is a solid, a liquid or a gas. The type of shine of the substance, if it is metallic, opaque, etc. The consistency of the substance, reporting if it is compact, powdery, lumpy or brittle.

Color

It is actually part of the physical appearance, but it is convenient to know the color of the flame that the substance produces when it is burned (flame test).

Odor

It indicates the characteristic smell of the substance, which, although it is a function of its chemical composition, is physically manifested without changing its composition. The type of odor the substance presents is identified; if it is acrid, sweet, fruity, resinous, floral, among other smells.

Taste

Identify the flavor type of the substance; whether it is bitter, sweet or salty. Sweet or salty are the main flavors, and can also be added if the substance is spicy, astringent or greasy.

Melting point

It is the temperature at which a substance goes from the solid state to the liquid state at a certain pressure.

Boiling point

It is the temperature at which a substance goes from the liquid state to the gaseous state at a certain pressure.

Sublimation

Some substances can go directly from the solid to the gaseous state, without going through the liquid state. The phenomenon occurs at temperature and pressure below the triple point of the substance.

Solubility

Indicates the mass of a substance that can be dissolved in a volume or mass of a given solvent (apolar or polar). This can be water, inorganic and polar solvent; ethanol, organic solvent and also polar; or benzene, organic solvent and apolar.

Hardness

Diamond

This property is commonly expressed on the Mohs scale, which was constructed based on the ability of one substance to scratch or be scratched by another. The scale goes from 1 to 10, with 10 corresponding to diamond hardness and 1 to talc.

Viscosity

This property is related to the resistance of a substance in liquid state to flow. It is also an expression of the friction encountered by a sheet of liquid to be displaced with respect to an adjacent one.

Surface tension

It is a consequence of the force of attraction, not compensated, exerted by the molecules of a substance within the liquid on the molecules of the substance that are on the surface of the liquid.

Electric conductivity

It is a measure of the ease with which electricity flows through a substance, being the inverse of its electrical resistance. It is usually noted whether the substance is a good or bad conductor of electricity.

Thermal conductivity

The coefficient of thermal conductivity is characteristic for each substance and measures its ability to conduct heat.

Ductility

It expresses the facility of a substance to be stretched to form threads or wires.

Malleability

The ease of a substance to be arranged in sheets that, even, can form rolls before it breaks.

Octanol partition coefficient value: water

It is the relationship between the concentration of a substance in octanol, a nonpolar substance, and in water, a polar substance. Using this value, it is known whether the substance is polar or nonpolar. The octanol: water partition coefficient value is usually expressed in log P or log K _ow.

Optical activity

It is the ability of a substance to rotate the plane of polarized light that falls on it. Substances that deflect polarized light to the right are called right-handed, and those that deflect it to the left are called left-handed.

Refractive index

It is a measure of the change of direction that a light ray experiences when it passes from a medium, generally air, to another medium formed by the substance in liquid or crystalline solid form.

Vapor pressure

Substances, including solids, at a certain temperature are capable of emitting vapors that exert pressure. This pressure is low, but measurable, and serves for the characterization of a substance.

Chemical properties

It is constituted by the properties that are manifested by altering the molecular or atomic structure of a substance when it interacts with another or changes its medium. Chemical properties are determined by tests of the reactivity of substances.

Chemical properties can be used to establish classifications of substances and / or elements or for their identification. A chemical property is said to be a property of matter that allows a change in composition.

Chemical properties include the following: pH, combustion, ionization energy, oxidation state, chemical reactivity, flammability, corrosion, toxicity, and chemical stability.

pH

It is a way of expressing the hydrogen concentration (pH = - log). The pH scale is between 0 and 14. A strong acid has a pH that is close to 0, while a strong base has a pH that is close to 14.

Combustion

It is the process by which a substance burns in the presence of oxygen, releasing heat and carbon dioxide (CO ₂). The substance that burns is transformed into its corresponding oxide.

Ionization energy

It is the energy necessary for the release of an electron to occur in an atom in the gas phase. The energy required for the exit of the first electron is less than that required for the release of the remaining electrons.

Oxidation states

Indicates the number of electrons that a chemical element needs to gain or give up to form complexes. The element can have many oxidation numbers, but a few are the most common.

Reactivity

It is the ease of a compound or element to react with another with which it combines to produce a product.

Inflammability

It is the tendency of a substance to burn. It is generally associated with the formation of vapors that can reach a flame, or an ease to combine with oxygen and ignite.

Corrosion

It is the ability of a substance to act on metals causing damage to its structure. Likewise, it can damage plant and animal tissues to produce their partial or total destruction.

Toxicity

It refers to the harmful action of a substance on living beings, especially man. For example, the contact of an acid with the skin, as well as the action of cyanide or arsenic that can cause the death of the individual.

Chemical stability

It is the property of a substance to maintain its chemical structure by not interacting or being susceptible to the action of oxygen or other gas present in the atmosphere. The more stable it is, the less risk it represents in its environment and the less rigorous its storage protocols will be.

Thermal decomposition

It is the chemical transformation that a substance undergoes when it is heated. The process is accompanied by the emission of fumes or vapors that can be toxic.

Themes of interest

Qualitative properties.

Quantitative properties.

General properties.

References

1. Whitten, Davis, Peck & Stanley. (2008). Chemistry (8th ed.). CENGAGE Learning.
2. Wikipedia. (2019). Matter. Recovered from: es.wikipedia.org
3. Helmenstine, Anne Marie, Ph.D. (October 04, 2019). Physical Properties of Matter. Recovered from: thoughtco.com
4. Derrick Arrington. (2019). Physical Property of Matter: Definition & Examples Video. Study. Recovered from: study.com
5. Chemistry LibreTexts. (September 18, 2019). Properties of matter. Recovered from: chem.libretexts.org