The plasma state of matter

In physics, each state of aggregation is a different form in which it matters. There are many possible states for ordinary matter, some well-studied and others only theoretical, but there are four that are generally thought of as four fundamental states: solid, liquid, gas, and plasma.

Plasma was first identified by William Crookes in 1879, who called plasma “radiant matter”, but as a state of matter it is a concept introduced by chemist Irving Langmuir during the 1920s.

It is generally understood to be a gaseous mixture of negatively charged electrons and positively charged ions, however the net charge of a plasma medium is neutral. In this state, matter has properties and triggers phenomena that do not occur in solids, liquids or gases, so it is considered as another state of matter.

Transition between ground states of matter

General features

The plasma state is achieved by heating a gas until the electrons have enough energy to separate from the atomic nuclei, forming ions and electrons that can move through the plasma and generating electric currents in the presence of a magnetic field. Although electrons and atoms are not bonded, they cannot be considered completely free particles, as they continue to maintain interaction forces between them within the plasma mass.

Each state of matter is distinguished by unique properties. The solid state has a defined volume and shape. The liquid state, on the other hand, has a definite volume but not a shape; the liquid can adapt to the shape of its container, but not its volume. Gas, on the other hand, has no defined volume or shape and can be adapted to both the shape and volume of its container.

Plasma shares certain properties with gases in that it is a fluid state with no definite shape or volume, but it has properties that do not occur in gases. Specifically, plasmas, because they contain charged particles, conduct electricity and react to magnetic fields creating electrical currents, while most gases are electrical insulators.

See also  What does a Chief of Police do?

Unlike the other three ground states, plasma does not exist in free form under surface conditions. our planet only occurs temporarily in some atmospheric phenomena, such as lightning, but they can be produced artificially by heating a gas or subjecting a gas to a strong electromagnetic field to cause electrons to separate from atomic nuclei. The formation of ions and the release of electrons can also occur by breaking molecular bonds.

In the Universe, however, plasma is the most common state of matter apart from dark matter, and is the predominant form of matter in stars, intracluster gases, and intergalactic regions.

types of plasma

Plasma is formed as a result of the ionization of atoms that form a gas. the degree of ionization fundamentally depends on the temperature; the higher the temperature, the greater the degree of ionization.

Depending on the degree of ionization, two types of plasma are distinguished:

Fully ionized plasmas: Also called hot plasmas. These are plasmas that have all or almost all of their particles ionized. Partially ionized plasmas: Also called cold plasmas if the degree of ionization is very low, but not to be confused with the plasma temperature, the temperature of a cold plasma can be very high. There are gases that with an ionization degree of only 1% can present plasma characteristics.

Partially ionized plasmas are those that can be seen in lightning storms and artificial plasmas such as neon lights or plasma televisions. Hot plasmas need conditions that can hardly be found on Earth but are very abundant in stars, for example the interior of the Sun and the solar corona are in a fully ionized state of hot plasma.

The rays are formed by a partially ionized plasma
See also  How can I become a victim advocate?

Another classification distinguishes thermal plasmas from non-thermal plasmas. In thermal plasmas, all the particles that form it are in thermal equilibrium, while in non-thermal plasmas the electrons are at a much higher temperature than the rest of the particles (ions and neutral plasma particles can even be at room temperature).

Phenomena associated with plasma

Plasma’s response to electromagnetic fields gives rise to various phenomena, such as filaments or stratification, which often display complex features, such as fractal shapes. Some of the most common phenomena are:

filament: formation of structures in the form of filaments known as birkeland currents. They are due to the displacement of charged particles along the lines of a magnetic field. They can be easily seen in plasma or lightning lamps. non-neutral plasmas: the good conductivity of plasmas causes the density of positive and negative particles to be homogeneously distributed, so plasmas are neutral or nearly neutral in any region. But there are plasmas with excess positive or negative charge that are not neutral. The most extreme case is plasmas formed by a single chemical species; for example, jets of charged particles, clouds of electrons or plasmas of positrons. Powder Plasmas: Dust plasmas are plasmas that contain suspended charged particles with sizes from millimeters (10-3 m) to nanometers (10-9 m). Due to their behavioral complexity, dust plasmas are also known as complex plasmas. Impervious plasmas: These are thermal plasmas that are impermeable to other gases and other cold or partially ionized plasmas. Filament in a plasma lamp

Application examples

Artificial plasmas are created by applying electric and magnetic fields to a gas. In this way, partially ionized plasmas can be created that are used in numerous applications, both industrial and domestic.

Plasmas are as common as neon lights, fluorescent lights, plasma displays, gas lasers or plasma lamps used for decoration. Other less everyday applications include controlled thermonuclear fusion and ionic propulsion.

See also  What Does a Forensic Mental Health Nurse Do?
Xenon ion thruster during testing at NASA’s Jet Propulsion Laboratory

Plasma in the Universe

An estimated 99% of the ordinary matter in the observable Universe is in the plasma state, although an estimated 90% of the matter that makes up the Universe is dark matter, a type of matter whose properties and states are still unknown.

Stars, stellar jets, extragalactic jets and the interstellar medium itself are examples of plasmas in the Universe. In the Solar System, the Sun and interplanetary space consist of plasma, as do the Earth’s magnetosphere or the ionosphere of comets and some planetary satellites.

orion nebula

However, many of these plasmas are extremely tenuous and have densities even lower than those achieved in the “vacuum conditions” of terrestrial laboratories. For example, the highest density in the magnetosphere is approximately 1000 particles per cubic centimeter and can be as low as 1 particle per cm3 in the less dense parts. Other plasmas, for example in stars, can have a much higher density and reach temperatures of millions of degrees Celsius.

Leave a Comment