Intensive and Extensive Properties of Matter (Meaning and Explanation)

We explain what the intensive and extensive properties of matter are, how they differ from each other and examples of each category.

Different pieces of metal are attracted to each other by their intensive properties. — Intensive and extensive properties are distinguished by whether or not they are affected by the amount of matter.

What are the intensive and extensive properties of matter?

The intensive and extensive properties of matter are all those magnitudes and characteristics that describe substances which are distinguished from each other depending on whether or not they are affected by the amount of matter available, that is, by the mass.

So, Intensive properties are those that do not depend on the amount of matter that a body has and that, therefore, are not additive. This means that if matter is divided into smaller fragments, these fragments will retain these same properties. For example, the density of a material (how closely its particles are arranged) does not depend on the size of the sample: a lead rod and a lead grain always have the same density.

Instead, When we talk about extensive properties, we are referring to those that do depend on the amount of matter that a body has, that is, they are additive properties, whose total value depends on the accumulation of the partial values of the parts of matter. For example, the weight of a body will depend on how much matter is being weighed, since a lead bar does not weigh the same as a grain of lead.

It is important to remember that All matter is endowed with both intensive and extensive properties since they are not mutually exclusive, they simply reflect different perspectives on the subject.

What are the intensive properties of matter?

Matter changes state when it passes through its melting and boiling points. — Intensive properties such as melting point do not vary with the amount of matter.

Intensive properties of matter are those that do not vary according to the amount of matter observed. can be classified into two groups: characteristic properties (which allow one substance to be distinguished from another based on its value) and general properties (which are common to different substances).

The main intensive properties of matter are:

The density. It is the relationship between the mass of a body and the volume it occupies, that is, how close the arrangement of its particles is, so that more or less matter can exist in the same space. This relationship is generally expressed in kilograms per cubic meter (kg/m³) or grams per cubic centimeter (g/cm³). For example, a sheet of aluminum has a density of 2 g/cm³exactly the same as a thick aluminum bar would have.
Viscosity. It is the resistance to flow that liquids and semi-solids present, due to the force of attraction that their particles exert on each other. This resistance normally depends on the temperature of the fluid (since by adding energy, the particles can move more), and is generally expressed in units of force per units of second, over units of surface area, for example, newtons per second per square meter (Ns/m²). For example, a drop of motor oil has a viscosity at 20°C of 0.03 Ns/m.²the same as a liter of the same substance would have.
The boiling point. It is the temperature range at which a liquid boils or boils, that is, it begins to turn into a gas (vapor). This property is expressed in degrees of temperature (Celsius, Fahrenheit or others) and can vary depending on the pressure to which the matter is subjected, but does not depend on the amount of the latter. For example, both a liter of water and a cup of water both boil at 100°C, although each will take a different time to reach that temperature.
melting point. It is the temperature range at which a solid body melts or melts, that is, it passes into the liquid state. This property is also expressed in degrees of temperature (Celsius, Fahrenheit or others) and can vary depending on the atmospheric pressure to which the matter is subjected, but does not depend on the amount of the latter. For example, an ice cube and a ton of ice melt, at standard pressure, both above 0 °C.
The hardness. It is the resistance that materials exert to physical alteration, such as penetration, abrasion, scratching, among others. There are different scales used in the industry to measure hardness (for example, the Mohs scale, which goes from 1 to 10), but it is always a property inherent to the nature of the matter, that is, to the arrangement of its particles. For example, gypsum (CaSO₄.2H₂O) it has a hardness of 2 on the Mohs scale, which allows you to scratch its surface with your fingernail with relative difficulty, regardless of whether it is a kilo of plaster or a ton.
The solubility. It is the ability of a substance to dissolve in another specific substance (a solvent). Not all substances dissolve in all solvents, but this relationship depends on the nature of the matter (its polar or nonpolar character, more specifically), and not on the amount of matter to be dissolved. However, there must always be an adequate relationship between the amount of substance to be dissolved and the solvent, since beyond a certain margin the latter can no longer assimilate any more amount of dissolved matter. Other factors that affect solubility are pressure and temperature. For example, a teaspoon of salt can dissolve in a glass of water, just as a kilo of salt can dissolve in a ton of water.
electrical conductivity. It is the ability of a substance to allow the flow of electrical energy through its particles, which depends on its atomic and molecular structure. Metals, for example, are good conductors of current because their atoms have mobile electrons in their surface layer, linked together with weak bonds. Conductivity is the opposite of resistance, and depends on certain physical factors of the matter, such as temperature. In addition, it is usually expressed in siemens per meter (S/m). Thus, for example, one meter of silver (Ag) and one kilometer of silver have the same electrical conductivity of 63 x 10⁶ at a temperature of 20 °C.
The pressure. It is a physical quantity that can be understood as the force that acts per unit area, expressed in newtons per square meter (Nm²) unit also called pascal (Pa). For example, when we talk about atmospheric pressure, we are referring to the force that the atmosphere exerts on the Earth's surface (1 atm). This pressure can vary depending on the altitude at which the surface is located, but it does not depend on the amount of gaseous matter or the surface: an atmosphere puts pressure on a centimeter of rock the same as it does on a kilometer.
The temperature. It is a physical quantity that expresses the amount of heat assimilated by a body, that is, the amount of kinetic energy that mobilizes its particles. This amount of energy is expressed in degrees (Celsius, Fahrenheit, among others) and does not depend on the amount of matter. For example, water can be heated to 70°C regardless of whether it is a liter or a glass.
The compressibility. It is the property of matter to reduce its volume when it is subjected to a certain pressure or compression, without changing the rest of its properties. Compressibility is also expressed in pascals, just like pressure, and does not depend on the amount of matter, but on the nature of the substance and the physical state it has: liquids and gases can be compressed, while solids are very difficult. to compress. For example, water has a compressibility of 45.8 pascals, regardless of whether it is a liter or an entire swimming pool.

What are the extensive properties of matter?

A weight is held by a string. — Extensive properties such as weight and volume change with mass.

The extensive properties of matter are those that vary depending on the amount of matter observed. are additive properties, that is, their values can be added as the matter accumulates: The total weight of a bronze bar increases if another identical bar is added to it. In addition, From the division of one extensive property and another, an intensive property is normally obtained: For example, dividing mass and volume gives density.

The main extensive properties of matter are:

Weight (P). It is the ratio of the force of gravity that acts on an object, or what is the same, the force that a body exerts on a support point, due to the action of a gravitational field on the mass of the object. This means that it depends on the gravitational force and the amount of matter (that is, the mass). Furthermore, like all forces, weight is represented as a vector and is expressed in newtons (N) or also in kilograms-force (kgf). Thus, for example, if we add two kilograms of lead, we will be increasing the amount of matter and also the resulting weight.
length (L) It is a fundamental magnitude, which indicates the distance between one point on a surface or an object and another and is normally expressed in meters (m), kilometers (km) or centimeters (cm). It is a linear dimension, which varies according to the amount of matter observed: the more matter or the more surface area, the greater the measured length. Thus, for example, a meter of land and a kilometer of land are two different measurements of length that express different amounts of surface area.
The volume (V). It is a scalar and three-dimensional magnitude, which expresses the amount of space that a body occupies. To do this, the unit of the cubic meter (m) is used.³) or the liter (l), the latter for liquids. Thus, 1 liter is equivalent to 0.001 cubic meters. There are, however, other units of volume in common use. In any case, the volume depends on the proportions of the body, that is, its amount of matter. For example, a liter of water represents a certain volume that will double if we add another liter and will triple if we add another.
The mass (M). It is a general property of matter, intrinsic to bodies, which refers to the amount of matter in a body, measured by the inertia it presents, that is, the resistance to displacement or movement. Normally expressed in kilograms, the mass of a body directly reflects the amount of matter that makes it up, so the more massive it is, the more matter it will have. For example, the mass of planet Earth is 5.972 x 10²⁴ kg, while that of the Moon is 7.349 x 10²² kg, which means that the Earth is more massive, that is, it contains more matter.
Strength (F). It is a vector magnitude that expresses the thrust necessary to vary the movement of a body (move it, accelerate it, slow it down, etc.) or to deform it. Expressed in newtons (N), it is a fundamental concept of physics, whose effects on a body depend largely on the amount of matter in it. Thus, to accelerate an object of mass 1 kg by 1 m/s, a force of 1 N is required, so that as the mass of the object increases (to 100 kg, for example), a proportional increase in the force.