Conservation of Charge

PhysicsElectric Charge and Static Electricity


A charge is a property of matter that causes and experiences electrical and magnetic effects. The basic concept behind charge conservation is that the system's total charge is conserved.

It can be defined as:

Atoms and molecules make up all of the materials in the world. Normally, all of these atoms and molecules are electrically neutral, with all of their charges balanced. One of the types of charges must be removed in order to electrify a neutral body.

A charged body always indicates either an electron deficit or an electron surplus. Electrons are assumed to be negatively charged. By removing some electrons from the atom, a body can be positively charged. Similarly, the same body can be negatively charged by gaining some electrons. In real life, whenever one body rubs against another.

One of the bodies loses electrons, while the other gains and becomes electrified as a result. The flow of charge causes electricity to flow. Some substances permit the passage of electricity through them, while others do not. These materials are classified as either conductors or insulators.


Conductors are substances that permit the passage of electricity through them. They have electric charges (electrons) that are relatively free to move around the conductor's body.

Examples: Metals, Human and Animal bodies


Insulators are substances that do not allow electricity to pass through them. They also have electric charges (electrons), but they cannot move freely within the body. As a result, this body is unable to conduct electricity.

Examples: Wood, rubber, clothes, etc.

Conservation of Charge

"Conservation of Charge is the principle that the total electric charge in an isolated system never changes. The net quantity of electric charge, the amount of positive charge minus the amount of negative charge in the universe, is always conserved."

The system, as we know, is a collection of objects whose interactions with charges are analogous to the conservation of energy and momentum. However, this conservation law is more intuitive because an object's net charge is determined by the number of electrons and protons. The protons and electrons cannot simply appear and disappear; the total charge must be the same. That's why a body always has the same number of electrons and protons.

Every atom is electrically neutral, containing the same number of electrons as protons in the nucleus. Body charges can also be whole multiples of the elementary charge: Electrons and protons contain electrical charge; the smallest charge that a body can have is the charge of one electron or proton.

For example, ${1.6\:\times\:10^{−19}C\:or\:+1.6\:\times\:10^{−19}C}$


The law of charge conservation states that the net charge of an isolated system will always remain constant. Let us try to get a better understanding of it. There is a list of basically two ideal states for a system with multiple objects.

  • The first is that all of the objects are net neutrally charged.

  • So there are the same number of protons and electrons in the entire system, and for each proton, there is an electron to balance it.

  • Another ideal state would be for the system's net charge to be distributed uniformly in the objects.

  • Rather than concentrating negative charge in a few bodies, the charge on the body is evenly distributed throughout by electron transfer, which can be accomplished by electron transfer from higher to lower polarity.

  • Only electrons, not protons, can be involved in charge transfer.

Conservation of Charge Examples

The conservation of charge principle states that no net charge can be produced. A few examples are provided below.

  • Charges as a result of induction

  • A proton decays into a positron and a neutron during radioactive decay, but no net charge is produced.

Images Coming soon

According to the above image, if our system is not influenced by any other charges, the net internal distribution of charges will continue in such a way that the overall net charge of the system will remain the same. In other words, charge can neither be created nor destroyed, and there is total charge conservation.


Electrons are one of the three major types of particles that comprise an atom. In contrast to protons and neutrons, which are made up of smaller, simpler particles, electrons are fundamental particles made up of no smaller particles. They are leptons, a type of fundamental particle. Every lepton has an electric charge of 1 or 0.

Electrons are extremely small particles. Because an electron's mass is only about 1/2000 that of a proton or neutron, electrons contribute almost nothing to the total mass of an atom. Electrons have an electric charge of one, which is equal to but opposite to a proton's charge of one. Because every atom has the same number of electrons as protons, positive and negative charges "cancel out." making atoms electrically neutral.


A proton is one of the three major particles that comprise an atom. Protons are found in the atom's nucleus. This is a tiny, dense region in the atom's core. Protons have a positive electrical charge of one (+1) and a mass of one atomic mass unit (amu), or approximately ${1.67\:\times\:10^{-27}}$ kilogrammes. Together with neutrons, they account for nearly all of an atom's mass.


Except for most hydrogen atoms, all atoms have neutrons in their nucleus. In contrast to protons and electrons, which are electrically charged, neutrons are electrically neutral. That's why the neutrons in the above diagram are labelled ${n^0}$. The zero represents "zero charge." A neutron's mass is slightly greater than a proton's mass, which is 1 atomic mass unit (amu). (An atomic mass unit is approximately ${1.67\:\times\:10^{-27}}$ kilogrammes.) A neutron has the same diameter as a proton, which is ${1.7\:\times\:10^{-15}}$ metres.


Q1. How many electrons are there in one Coulomb of charge?

Ans. Using the formula, Q = ne, we get

$\mathrm{n = Q/e}$

$\mathrm{n = 1/ (1.6\: X\: 10^{-19})}$

Therefore, $\mathrm{n = 6.25\: x \:10^{18}}$

Q2. What happens to the radius of a soap bubble when its charge is negative?

Ans. As the charge of the soap bubble becomes negative, the radius of the bubble increases due to repulsive force.

Q3. Is it possible to have a charge with a value of $\mathrm{1.6 \:x \:10^{-20}\:C}$?

Ans. No, a charge of $\mathrm{1.6 \:x \:10^{-20}\:C}$ is not possible because it is 1/10 of an electronic charge and thus not an integral multiple.

Q4. Consider two copper spheres of equal radius, one solid and the other hollow. Which copper sphere has the higher charge?

Ans. Because the charges reside on the surface of the material, both copper spheres will have an equal charge. Because both spheres have the same radius, they will have the same charge.

Q5. What is specific charge?

Ans. The specific charge is the ratio of an ion's or subatomic particle's charge to its mass.

Updated on 13-Oct-2022 11:19:47