What is "electric charge"

Electricity \E`lec*tric"i*ty\ ([=e]`l[e^]k*tr[i^]s"[i^]*t[y^]), n.; pl. Electricities ([=e]`l[e^]k*tr[i^]s"[i^]*t[i^]z).

1. (Physics) a property of certain of the fundamental particles of which matter is composed, called also electric charge, and being of two types, designated positive and negative; the property of electric charge on a particle or physical body creates a force field which affects other particles or bodies possessing electric charge; positive charges create a repulsive force between them, and negative charges also create a repulsive force. A positively charged body and a negatively charged body will create an attractive force between them. The unit of electrical charge is the coulomb, and the intensity of the force field at any point is measured in volts.

2. any of several phenomena associated with the accumulation or movement of electrically charged particles within material bodies, classified as static electricity and electric current. Static electricity is often observed in everyday life, when it causes certain materials to cling together; when sufficient static charge is accumulated, an electric current may pass through the air between two charged bodies, and is observed as a visible spark; when the spark passes from a human body to another object it may be felt as a mild to strong painful sensation. Electricity in the form of electric current is put to many practical uses in electrical and electronic devices. Lightning is also known to be a form of electric current passing between clouds and the ground, or between two clouds. Electric currents may produce heat, light, concussion, and often chemical changes when passed between objects or through any imperfectly conducting substance or space. Accumulation of electrical charge or generation of a voltage differnce between two parts of a complex object may be caused by any of a variety of disturbances of molecular equilibrium, whether from a chemical, physical, or mechanical, cause. Electric current in metals and most other solid coductors is carried by the movement of electrons from one part of the metal to another. In ionic solutions and in semiconductors, other types of movement of charged particles may be responsible for the observed electrical current. Note: Electricity is manifested under following different forms:

   1. Statical electricity, called also

      Frictional electricity or Common electricity, electricity in the condition of a stationary charge, in which the disturbance is produced by friction, as of glass, amber, etc., or by induction.

   2. Dynamical electricity, called also

      Voltaic electricity, electricity in motion, or as a current produced by chemical decomposition, as by means of a voltaic battery, or by mechanical action, as by dynamo-electric machines.

   3. Thermoelectricity, in which the disturbing cause is heat (attended possibly with some chemical action). It is developed by uniting two pieces of unlike metals in a bar, and then heating the bar unequally.

   4. Atmospheric electricity, any condition of electrical disturbance in the atmosphere or clouds, due to some or all of the above mentioned causes.

   5. Magnetic electricity, electricity developed by the action of magnets.

   6. Positive electricity, the electricity that appears at the positive pole or anode of a battery, or that is produced by friction of glass; -- called also vitreous electricity.

   7. Negative electricity, the electricity that appears at the negative pole or cathode, or is produced by the friction of resinous substance; -- called also resinous electricity.

   8. Organic electricity, that which is developed in organic structures, either animal or vegetable, the phrase animal electricity being much more common.

3. The science which studies the phenomena and laws of electricity; electrical science.

4. Fig.: excitement, anticipation, or emotional tension, usually caused by the occurrence or expectation of something unusual or important.

electric charge \electric charge\, electrical charge \electrical charge\, same as electricity[1].

n. 1 (context physics English) the static electric energy of a charged body 2 (context physics English) the quantity of unbalanced positive or negative ions in or on an object; measured in coulombs 3 (context physics English) a quantum number of some subatomic particles which determines their electromagnetic interactions; by convention the electron has an electric charge of -1, the proton +1 and quarks have fractional charge

n. the quantity of unbalanced electricity in a body (either positive or negative) and construed as an excess or deficiency of electrons; "the battery needed a fresh charge" [syn: charge]

Electric charge is the physical property of matter that causes it to experience a force when placed in an electromagnetic field. There are two types of electric charges: positive and negative. Like charges repel and unlike attract. An object is negatively charged if it has an excess of electrons, and is otherwise positively charged or uncharged. The SI derived unit of electric charge is the coulomb (C). In electrical engineering, it is also common to use the ampere-hour (Ah), and, in chemistry, it is common to use the elementary charge (e) as a unit. The symbol Q often denotes charge. Early knowledge of how charged substances interact is now called classical electrodynamics, and is still accurate for problems that don't require consideration of quantum effects.

The electric charge is a fundamental conserved property of some subatomic particles, which determines their electromagnetic interaction. Electrically charged matter is influenced by, and produces, electromagnetic fields. The interaction between a moving charge and an electromagnetic field is the source of the electromagnetic force, which is one of the four fundamental forces (See also: magnetic field).

Twentieth-century experiments demonstrated that electric charge is quantized; that is, it comes in integer multiples of individual small units called the elementary charge, e, approximately equal to (except for particles called quarks, which have charges that are integer multiples of e). The proton has a charge of +e, and the electron has a charge of −e. The study of charged particles, and how their interactions are mediated by photons, is called quantum electrodynamics.