What is Electricity?

Electricity is:​

“A form of energy resulting from the existence of charged particles (such as electrons or protons), either statically as an accumulation of charge or dynamically as a current.”

“A state or feeling of thrilling excitement.” We are interested in the first bullet point, obviously, more specifically in current
electricity, which is the one that powers our electronic gadgets.

To understand the basics of electricity we need to focus in atoms, the basic building blocks of matter.

Electricity:​

Electricity appears as a form of energy due to the existence of electrically charged particles, the protons and the electrons on the structure of the atom see picture below.

Structure of an atom:​

The electrons are negatively charged and spin around the center of the atom, which is the nucleus. The nucleus is made up of neutrons and protons. The protons are positively charged and the neutrons are not charged.
Electrons can move from one atom to another. An electric current, basically, is a flow of electrons bumping from atom to atom.

This phenomenon happens only in some materials, the ones that have conductive properties, the conductors , like copper for example

Current:​

When a flux of electrons goes from atom to atom, that phenomenon is called electric​

current . Basically, current is a flow of electrically charged particles through a conductive material.

The wires used in electronics have copper in them to get the current flowing and are covered by a non-conductive material, also called an insulator , through which the electrons cannot pass.

In a circuit, the charged particles flow through wires and if the wire is cut, the current stops flowing.

That’s why in an opened circuit nothing happens:

Voltage:​

Charged particles are found in all cables. For electrons to flow from one atom to another, they require energy, which is provided by the voltage. To produce the energy, a voltage source is required. Voltage is defined as the force that propels an electric current ahead. A voltage source is a battery that generates an electric field that drives charged particles along.

Resistance:​

Electrical resistance is another important concept in electricity. Every electronic component has some resistance, which is defined as a material's ability to resist electric current. The current must be pushed through this material, which necessitates a higher voltage. We call this a voltage drop in the resistive component when this happens.

 

Measuring Current, Voltage and Resistance