What is Electricity?

How Tiny Particles Create the Energy That Powers Our World

Author

CuriosityQuest
August 30, 2025

Atoms are made up of 3 particles, two of which are found at the center (the nucleus), which are protons and neutrons. Protons are positively charged, while neutrons have a neutral charge. Surrounding the nucleus are different layers of orbital shells, in which electrons “orbit” around the nucleus.

Electrons are negatively charged and are attracted to the positive charge of the protons. There is a set number of how many electrons that can be in an orbital shell. The number of protons, neutrons, and electrons that an atom has tells us which material it is. Atoms hold on to their electrons very tightly, but some materials hold them tighter than others. The outermost shell is the valence shell, in which some materials have loosely bound electrons that can go to other atoms. Atoms that can pass electrons are called conductors, and most metals are conductors. Atoms that don’t have free electrons, so they can’t pass electrons to other atoms, are called insulators (glass, rubber).

If we look inside a copper cable, we can see that the free electrons are able to move to other atoms randomly in any direction. If we connect the copper cable to a closed circuit with a power source, like a battery, the voltage will force the electrons to move in the same direction to try to get back to the other terminal of the battery.

  • Circuit: The route electrons can flow along.

  • Closed Circuit: Electrons can flow around.

  • Open Circuit: Electrons cannot flow around.

  • Voltage: Pushing force of electrons within a circuit. (Like pressure in a water pipe). Joule / Coulomb

  • Current: Flow of electrons (Measured in Amps) past a point in a circuit within a set amount of time. 1 Amp = 1 Coulomb.

  • Resistance: A restriction to the flow of electrons (Measured in Ohms). It happens when electrons collide with atoms (Copper has a lower collision rate, but iron has more).

  • Resistor: Protect components by restricting the flow of current.

Electrons are negatively charged, so they flow from the negative terminal to the positive terminal.

  • The longer the wire, the greater the resistance

  • The thicker the wire, the lower the resistance

  • Every material has a different resistance

  • Temperature changes resistance

  • Current passing through a coil generates a magnetic field.

The two primary forms of electricity are static and current electricity.

  • Static Electricity: This is an accumulation of electric charges on the surface of an object. The charge is "at rest" until it is released, often as a sudden spark or shock. A common example is rubbing a balloon on your hair, which causes electrons to transfer, giving the balloon a negative charge and making your hair stand up.

  • Current Electricity: This is the continuous flow of charges, and it is the kind of electricity that powers our homes and devices. There are two main types of current:

    • Direct Current (DC): The flow of electrons is in a single, constant direction, as seen in batteries and solar cells.

    • Alternating Current (AC): The flow of electrons periodically reverses direction. This is the type of electricity that is sent from power plants to your home's wall outlets.

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