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Value of Electron

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Last updated date: 28th Mar 2024
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What is the Value of Electrons?

An electron is a subatomic (smaller than an atom) light particle that carries a single unit of negative electricity, represented as - e. Electrons can either be free (meaning not attached to the atom) or bound with the nucleus. The charge of the electron is equal to the magnitude of the elementary charge (e) however, holding a negative sign (-e), the value of the basic unit of charge or elementary charge is 1.6 x 10-19 C. Therefore, 


Value of electron charge (- e) =  -1.6 x 10-19 Coulomb


It is one of the important constants of nature.


Electron Charge

The charge on a single electron (e) is regarded as the unit electrical charge. It is designated as a negative polarity. The charge on an electron is equal, however, opposite to the positive charge on a proton or hole.


Mass of Electron

Electrons have a mass of 0 amu (atomic mass unit) when they orbit the nucleus and have a charge of -1. 


The invariant mass of the electron is given by,


m (-e)  =  9.1 x 10-31 kg


Which is a very small value.


Here, the invariant mass is the rest mass mass or the mass of a stationary electron.


In atomic mass units (amu), the mass of an electron is given by,


5.489×10-4 amu


Charge of Electron in eV

The charge of an electron is -1, and its mass is  about 1/2000 of the mass of a neutron or proton. The electron charge is usually represented by the symbol e. This is the basic physical constant  used to represent 1.1602 × 10-19 coulomb, a unit of naturally occurring charge. Therefore, the charge of the electron is 1.602 x 10-19 C.  In the centimeter gram second unit system  (CGS), it is 4.80320425 (10) x 10-10 statcoulomb. 


In physics, eV stands for electron volt and it is the amount of kinetic energy gained by an electron while accelerating from rest  position through an electric potential difference of one volt in vacuum.


Electron volt is the unit of energy generally used in atomic and nuclear physics which is equal to the energy gained by an electron  or a charged particle carrying unit electric charge when the electrical potential at the electron increases by 1 Volt. 


1 Electron volt (eV) =  1.6 x 10-12 erg


Where value of 1 erg = 10-7 Joule

So,

 

The electron volt =  1.6 x 10-19 Joule


Mass of an Electron 

The mass of an electron is known to be 1/1836 of the mass of a proton. The  electron mass values ​​are: 

me ​​= 9.10938356 × 10-31 kg 


Electron charge and mass values ​​are often used to solve physical problems.


Mass of an electron in eV or electron volt is this mass corresponding to a rest energy given by,


mev =  0.511 MeV


Value of Charge

The quantization of electric charge is the property by virtue of which all free charges are an integral part of a basic unit of charge represented by e. Therefore, the charge q of a body is given by,

                       

q  = ne 


Where n is any integer, positive or negative. The fundamental charge is the charge that an electron or proton carries,  by convention, the charge on an electron is negative. Therefore, charge on an electron is written as (e -1) while the charge on proton is (+e).


The value of the basic unit of elementary charge is given by,  


e = 1.6  x  10-19 coulomb or C


This is one of the fundamental constants used in physics.


If a body carries n1 electrons and n2 protons,then total charge on the body will be:


  q  =  n1(-e) + n2 (e) = (n2 - n1) e


As n1, n2 are integers so their difference must also be an integer. Hence the charge on any body is an integral multiple of e. 


q  = + / - n x 1.6 x 10-19 C


The SI unit of charge is coulomb or C.


The CGS (centimeter-gram-second) unit of charge is 1 electrostatic (e.s.u) of charge or stat charge.


Another unit of charge is one electromagnetic unit (e.m.u) of charge, where      

 

1 e.m.u. of charge = 3 x 108 e.s.u of charge = 10 Coulomb


Charge of One Electron

Any charged body or charged particle can possess charge equal to +/- e , +/- 2e, +/- 3e, +/- 4e and so on, i.e The possible value of charge for one electron will be given by.


Taking the equation: q  = ne (putting n = 1), we get,


  q  = - 1 e = - 1.6 x 10-19 Coulomb


Energy Level 

Atoms have several energy bands and energy gaps. All electrons are situated in one of the energy bands. Every atom has a valence band and a conduction band. The gap which is present between the two bands, valence band and the conduction band, is what we call the forbidden energy gap. The gap also determines the electrical properties of the material. 


Difference Between Charge and Electron


S.No

Charge

Electron

1.

Electric charge on a body can either be positive, negative or zero. They represent either deficiency or excess of electrons on them.

Electrons carry a negative charge of a particular value in coulombs.

2.

Electric charge is the physical attribute of the body that causes it to experience a force when located in an electric or a magnetic field.

Electron is a stable light subatomic particle with a charge, found in all atoms, acts as the primary carrier of electricity in conductors.

3.

Charge is an attribute that particles have when they are not neutral.

Electrons have the most stable electronic configuration that are responsible for all the physical and chemical phenomena in the world.


About Electrons

Electrons are small subatomic particles that orbit the nucleus in an energy shell called an orbit. These subatomic particles carry a negative charge of 1.602 × 10-19 coulombs. The electron mass  is 9 × 10-31 kg. Electrons orbit the core within the shell, continuously  increasing energy. H. Shells closer to the core have less energy than the outermost shells. Electrons which are available in the outermost shell of an atom are called valence electrons. The vertical groups in the periodic table represent the valence electrons of an atom, that is, the number of electrons present in the  valence electrons.


Valence Electrons 

Simply put, valence electrons are  electrons that are constantly rotating in the outermost shell or orbit of an atom. The outermost shell, or  valence shell, is the shell with the highest energy. Therefore, the electrons  in the valence shell have the highest energy compared to the electrons  in the internal orbit. This shell is at a distance away from the core. As a result, they can be attracted to the nucleus of another atom as much as or more than they are in their nucleus.


These electrons exist in the s orbital and the p orbital. The electrons that exist in the inner shell are core electrons. During the formation of chemical bonds, there is a  loss, gain, or sharing of valence electrons. Valence electrons play an important role in most chemical reaction because they contain more energy than  electrons  in internal orbitals. In addition, valence electrons are characteristic of the Chemistry of elements. Valence electrons give us an idea of ​​how easy it is for an atom to form a bond, how many unpaired electrons there are, and how many atoms can participate in a given chemical reaction. 

FAQs on Value of Electron

1. What do you understand by the term quantum of charge?

Most  elementary particles usually have an electric charge that is an integral multiple of 1/3e. Therefore, it can be said that the "charge quantum" is 1/3e. 


 It can be said that the "elementary charge" is three times  the "charge quantum". 

2. What do you understand by the term valency?

Valency is defined as the capacity of an atom to join with another atom either by losing, gaining or sharing of their electrons. 

3. What are the methods to fill atomic orbitals?

There are three methods to fill atomic orbitals

  • Aufbau Principle

  • Pauli Exclusion Principle

  • Hund’s Rule 

4. What do you understand by electron shells?

An atom is made up of a series of shells around its core that holds the electrons of the atom. An electron shell usually consists of one or more subshells. The electron shell determines the electron configuration of an atom. Total number of electrons that can be accommodated in each shell is calculated by 2n2. Where n is the number of  shells of electron. The first electron shell can hold only two electrons, and as the  number of shells increases, the number of electrons that can be accommodated increases. This orbit is filled first before the next orbit. 

5. What are the common characteristics of an electron?

Electrons are negatively charged particles with a very small mass. The mass and charge of the electron are shown below. 


(I) Electron mass (me): The electron  mass  is about 1/1840 times that of a hydrogen atom. 

6. Write properties of an electron.

All matter consists of atoms that, in turn, contains protons, neutrons and electrons. Out of these three, electrons are the subatomic particles and they are incapable of being broken and they have three fundamental attributes:

  • Spin: They spin about an axis in a way similar to that of planets.

  • Mass: The rest mass of an electron is 9.1 x 10-31 kg or 5.489 x 10- 4 amu.

Charge: Electrons are negatively charged in nature and have an electric charge of 1.6 x 10-19 C, which is used as a standard unit of charge for subatomic particles.

7. What will happen to the mass of an electron if it travels with the velocity of light?

Since the electrons have a stationary or rest mass as 9.1 x 10-31. However, when an electron starts moving with the velocity of light that means the speed of electron (v)  becomes equal to the speed of light (c) . The mass of the electron would start varying and such variations would be infinite.

8. Write the value of mass of an electron in grams.

The mass of an electron in kg is 9.1 x 10-31 kg. Since 1 kg  = 1000 g


Therefore, the mass of an electron in grams is 9.1 x 10-28 g.

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