What is electric charge?

Electric charge is a basic property of matter carried by some elementary particles that dictates how these particles interact with electric and magnetic fields. It exists in two forms: positive and negative. Like charges repel, while opposite charges attract. Electric charge is found in natural units, such as the charge of an electron or proton, a fundamental physical constant. The standard unit of electric charge is the coulomb (C), defined as the amount of charge flowing through a conductor cross-section in one second with a current of one ampere. Electric charge is conserved, meaning the total electric charge in an isolated system remains constant.

What are the two types of electric charge?

Electric charge is a basic property of matter carried by elementary particles that dictates how they interact with electric or magnetic fields. There are two types of electric charges: * Positive * Negative Objects with an excess of one type of charge repel each other, while those with opposite charges attract. The negative charge of an electron equals the positive charge of a proton , a fundamental physical constant. Atoms are neutral because they contain an equal number of protons and electrons. An object becomes positively charged when it loses electrons and negatively charged when it gains electrons.

How do like and unlike charges interact with each other?

The electric force between charges at rest is described by Coulomb's law . Electric charges are of two types, positive and negative. Like charges repel each other, while unlike charges attract. The attraction or repulsion acts along the line between the two charges. The size of the force is proportional to the value of each charge. The force is inversely proportional to the square of the distance between the two charges; if the distance doubles, the attraction or repulsion becomes weaker, decreasing to one-fourth of its original value.

How is electric charge measured?

Electric charge, a fundamental property of matter, is measured using various methods that rely on the interactions between charged objects and electric fields. The unit of electric charge in the SI system is the coulomb (C), which is defined as the amount of electric charge that flows through a conductor's cross-section in one second when the current is one ampere. An early method for detecting the presence of electric charge is the electroscope , which uses the repulsion of like charges to indicate a charge. More modern techniques, such as electroanalytical methods , employ electrodes to measure electrical parameters of a solution, relating these measurements to the quantity of the analyte in the solution. These methods include potentiometry, amperometry, and coulometry, each measuring different electrical properties to determine charge.

What particles in atoms carry electric charge?

Elementary particles called electrons and protons carry electric charge in atoms. Electrons have a negative charge, while protons have a positive charge. The negative charge of an electron is equal in magnitude to the positive charge of a proton. Neutrons are neutral subatomic particles, meaning they have no electric charge. Atoms are electrically neutral because they contain an equal number of protons and electrons.

How does electric charge relate to static electricity and electric current?

Electric charge is a basic property of matter carried by elementary particles that determines how they interact with electric and magnetic fields. It can be positive or negative, and it is conserved, meaning it can't be created or destroyed. Static electricity arises from an imbalance of electric charges within a material, typically when electrons move from one material to another, creating a buildup of charge. When this charge is allowed to flow, it becomes an electric current , which is the flow of electric charge, usually electrons, through a conductor.

electric charge

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Diagram of the Millikan oil-drop experiment showing a chamber with oil droplets sprayed from an atomizer, falling between two charged metal plates. A light source and viewing microscope are used to observe the droplets, which are influenced by electric and ionizing radiation to measure their charge.

electrical charge distribution in a thunderstorm

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Key People:: Charles François de Cisternay Du Fay; George Johnstone Stoney

Related Topics:: Coulomb force; charge conservation; charge carrier; point charge; charge transfer

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Also known as: charge, electrical charge

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Oct. 29, 2026 •History

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Sound-levitated particles reveal how static charge builds up • Oct. 28, 2026, 8:00 AM ET (Phys.org)

Top Questions

What is electric charge?
Electric charge is a basic property of matter carried by some elementary particles that dictates how these particles interact with electric and magnetic fields. It exists in two forms: positive and negative. Like charges repel, while opposite charges attract.

Electric charge is found in natural units, such as the charge of an electron or proton, a fundamental physical constant. The standard unit of electric charge is the coulomb (C), defined as the amount of charge flowing through a conductor cross-section in one second with a current of one ampere. Electric charge is conserved, meaning the total electric charge in an isolated system remains constant.
4 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
What are the two types of electric charge?
Electric charge is a basic property of matter carried by elementary particles that dictates how they interact with electric or magnetic fields.

There are two types of electric charges:
* Positive
* Negative

Objects with an excess of one type of charge repel each other, while those with opposite charges attract. The negative charge of an electron equals the positive charge of a proton, a fundamental physical constant. Atoms are neutral because they contain an equal number of protons and electrons. An object becomes positively charged when it loses electrons and negatively charged when it gains electrons.
4 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
How do like and unlike charges interact with each other?
The electric force between charges at rest is described by Coulomb's law. Electric charges are of two types, positive and negative.

Like charges repel each other, while unlike charges attract. The attraction or repulsion acts along the line between the two charges. The size of the force is proportional to the value of each charge. The force is inversely proportional to the square of the distance between the two charges; if the distance doubles, the attraction or repulsion becomes weaker, decreasing to one-fourth of its original value.
6 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
How is electric charge measured?
Electric charge, a fundamental property of matter, is measured using various methods that rely on the interactions between charged objects and electric fields. The unit of electric charge in the SI system is the coulomb (C), which is defined as the amount of electric charge that flows through a conductor's cross-section in one second when the current is one ampere.

An early method for detecting the presence of electric charge is the electroscope, which uses the repulsion of like charges to indicate a charge. More modern techniques, such as electroanalytical methods, employ electrodes to measure electrical parameters of a solution, relating these measurements to the quantity of the analyte in the solution. These methods include potentiometry, amperometry, and coulometry, each measuring different electrical properties to determine charge.
4 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
What particles in atoms carry electric charge?
Elementary particles called electrons and protons carry electric charge in atoms. Electrons have a negative charge, while protons have a positive charge. The negative charge of an electron is equal in magnitude to the positive charge of a proton. Neutrons are neutral subatomic particles, meaning they have no electric charge. Atoms are electrically neutral because they contain an equal number of protons and electrons.
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Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
How does electric charge relate to static electricity and electric current?
Electric charge is a basic property of matter carried by elementary particles that determines how they interact with electric and magnetic fields. It can be positive or negative, and it is conserved, meaning it can't be created or destroyed.

Static electricity arises from an imbalance of electric charges within a material, typically when electrons move from one material to another, creating a buildup of charge. When this charge is allowed to flow, it becomes an electric current, which is the flow of electric charge, usually electrons, through a conductor.
5 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

electric charge, basic property of matter carried by some elementary particles that governs how the particles are affected by an electric or magnetic field. Electric charge, which can be positive or negative, occurs in discrete natural units and is neither created nor destroyed.

Electric charges are of two general types: positive and negative. Two objects that have an excess of one type of charge exert a force of repulsion on each other when relatively close together. Two objects that have excess opposite charges, one positively charged and the other negatively charged, attract each other when relatively near. (See Coulomb force.)

Many fundamental, or subatomic, particles of matter have the property of electric charge. For example, electrons have negative charge and protons have positive charge, but neutrons have zero charge. The negative charge of each electron is found by experiment to have the same magnitude, which is also equal to that of the positive charge of each proton. Charge thus exists in natural units equal to the charge of an electron or a proton, a fundamental physical constant. A direct and convincing measurement of an electron’s charge, as a natural unit of electric charge, was first made (1909) in the Millikan oil-drop experiment. Atoms of matter are electrically neutral because their nuclei contain the same number of protons as there are electrons surrounding the nuclei. Electric current and charged objects involve the separation of some of the negative charge of neutral atoms. Current in metal wires consists of a drift of electrons of which one or two from each atom are more loosely bound than the rest. Some of the atoms in the surface layer of a glass rod positively charged by rubbing it with a silk cloth have lost electrons, leaving a net positive charge because of the unneutralized protons of their nuclei. A negatively charged object has an excess of electrons on its surface.

Italian-born physicist Dr. Enrico Fermi draws a diagram at a blackboard with mathematical equations. circa 1950.

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Physics and Natural Law

Electric charge is conserved: in any isolated system, in any chemical or nuclear reaction, the net electric charge is constant. The algebraic sum of the fundamental charges remains the same. (See charge conservation.)

The unit of electric charge in the metre–kilogram–second and SI systems is the coulomb and is defined as the amount of electric charge that flows through a cross section of a conductor in an electric circuit during each second when the current has a value of one ampere. One coulomb consists of 6.24 × 10¹⁸ natural units of electric charge, such as individual electrons or protons. From the definition of the ampere, the electron itself has a negative charge of 1.602176634 × 10⁻¹⁹ coulomb.

An electrochemical unit of charge, the faraday, is useful in describing electrolysis reactions, such as in metallic electroplating. One faraday equals 96485.332123 coulombs, the charge of a mole of electrons (that is, an Avogadro’s number, 6.02214076 × 10²³, of electrons).

The Editors of Encyclopaedia Britannica This article was most recently revised and updated by Erik Gregersen.

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