1. Static Electricity (SE)
Static electricity is the build-up of electric charge on the surface of an object. It happens when electrons (which are negatively charged particles) are transferred from one object to another, usually by friction (rubbing). The charges in static electricity do not flow continuously — they stay still, which is why we call it "static."
This charge will remain on the surface until it is released or discharged, either suddenly (like a small spark) or slowly into the air or ground.
2. Force Between Positive and Negative Electric Charges
In physics, opposite charges attract and like charges repel. This means:
A positive charge (deficient in electrons) will attract a negative charge (has extra electrons).
Two positive charges repel each other.
Two negative charges also repel each other.
This attraction or repulsion between charges is due to the electrostatic force, also known as Coulomb’s force. It is a non-contact force that acts at a distance.
3. Gaining and Losing Electrons (Formation of Charge)
Atoms are made of protons (positive), neutrons (neutral), and electrons (negative). Normally, an atom has equal numbers of protons and electrons, making it electrically neutral.
When an object gains electrons, it becomes negatively charged because it now has more negative particles than positive.
When an object loses electrons, it becomes positively charged because it now has more protons than electrons.
This imbalance between the number of protons and electrons is what creates electric charge.
4. Conductors and Insulators
A conductor is a material that allows electric charges (especially electrons) to move freely through it. Metals like copper, aluminum, and gold are good conductors because they have free electrons that can move easily.
An insulator is a material that does not allow charges to move easily. Materials like rubber, plastic, wood, and glass are insulators. In these materials, the electrons are tightly bound to atoms and cannot move freely.
Because of this difference:
Conductors do not hold static electricity well — the charge spreads out or flows away.
Insulators can hold static charge because the electrons cannot move freely.
5. Charging and Discharging
Charging is the process of adding or removing electrons from an object to create an electric charge. This can happen by friction, contact, or induction.
Discharging is the process where the built-up charge is released, usually by giving the electrons a path to escape (such as touching a conductor or connecting to the Earth). When this happens quickly, it may cause a spark or a shock.
6. Electrostatic Charge
An electrostatic charge is the electric charge that builds up on the surface of a material when electrons are added or removed. It is a static (non-moving) charge. This charge can remain on insulators for a long time and can cause attraction, repulsion, or even discharge when near a conductor.
7. Positive and Negative Charges
A positive charge means the object has lost electrons and now has more protons than electrons.
A negative charge means the object has gained electrons and has more electrons than protons.
These charges interact with each other through electrostatic forces:
Opposites attract (positive attracts negative),
Likes repel (positive repels positive, and negative repels negative).
8. Friction and Charging
When two different materials are rubbed together, friction causes electrons to be transferred from one object to the other. This is called charging by friction.
The object that gains electrons becomes negatively charged.
The object that loses electrons becomes positively charged.
This method works well with insulating materials, such as rubbing a plastic rod with a cloth or a balloon on hair.
✅ Final Summary:
Static electricity happens when objects gain or lose electrons, usually by rubbing. The imbalance of charges leads to electrostatic forces, which can attract or repel objects. Conductors let charges move freely, while insulators hold them in place. Charging is the act of creating this imbalance, and discharging is the process of releasing it. Positive and negative charges form when electrons are lost or gained. All of this is governed by the behavior of electric charges and how they move or stay still on different materials.
