Electricity: Static Electricity

Understanding Static Electricity

Static electricity is the build-up of electric charge on the surface of objects.
This build-up of charge is due to the transfer of electrons and can occur when two different materials come into contact and then separate. This is known as frictional charging.
An object becomes positively charged when it loses electrons, and negatively charged when it gains electrons.
Unlike charges (positive and negative) attract each other whereas like charges (positive-positive or negative-negative) repel each other.
The law that describes these interactions is Coulomb’s law.
An object can be discharged by providing a path for the electrons to move off the object. This can be done using a grounding wire.
The phenomenon of static electricity can cause sparks. These occur when the electric field becomes strong enough to ionise the air particles, creating a path for a sudden flow of electrons (the spark).

Static Electricity in Everyday Life

Static electricity can be observed in a number of everyday situations, such as clothes sticking together when fresh out of the dryer, or the shock we get when touching a metal doorknob after walking across a carpeted floor.
Lightning is a natural and large-scale example of static discharge. It’s caused by the build-up of electric charge in storm clouds.
Electrostatic precipitators are used in industry to reduce air pollution. They give dust and smoke particles a charge so they’re attracted to the plates in a chimney stack, preventing them from being released into the atmosphere.

Understanding these core topics around static electricity will lay a solid foundation for exploring more complex concepts related to electricity and magnetism.