Electricity basics

What Is Electricity?

  • Grades 3-8
  • 10 minute activity
  • NGSS 4-PS3-2

Quick answer

Electricity is energy carried by tiny moving particles that have an electric charge. In a wire, those particles are electrons. When charges flow around a complete loop, called a circuit, they carry energy from a power source like a battery to things that use it, like a light, a buzzer or a motor.

Dough circuit with magnified views of electrons drifting through the copper wire and charged salt ions moving through the dough
Tap to enlarge. In the copper wire, electrons drift along. In the salty dough, charged bits of salt called ions carry the electricity.

Atoms, electrons and charge

Everything around you is made of atoms. Atoms are far too small to see, but they are made of even smaller parts. In the middle is the nucleus, which holds protons with a positive charge. Around the outside are electrons with a negative charge.

Opposite charges pull toward each other and matching charges push apart. In most materials, the electrons stay close to their own atoms. In metals like copper, some electrons can hop from atom to atom. When a battery gives them a push, they all start drifting the same way. That flow of charge is electric current.

Electricity needs a loop

A battery has two ends. One end pushes charges out and the other end pulls them back in. Electricity only flows when there is a complete path, or circuit, from one end of the battery to the other. Break the path anywhere and the flow stops everywhere.

In a dough circuit, the red wire, the dough, the LED and the black wire make that path. Learn more in What Is a Circuit?.

Electricity carries energy

The battery stores energy in chemicals. Electricity carries that energy around the circuit. The parts in the circuit change it into something you can see, hear or feel.

Battery holder sending electricity to an LED for light, a buzzer for sound and a motor for motion
Tap to enlarge. An LED changes electrical energy into light, a buzzer into sound and a motor into motion.

This is why electricity is so useful. The same energy can light a room, play music, cook food or run a computer, depending on what it flows through.

Static electricity vs. current electricity

Static electricity

  • Charge builds up in one place and stays put
  • Made by rubbing things together, like a balloon on your hair
  • Lets go all at once as a spark or a zap
  • Lightning is a giant static discharge

Current electricity

  • Charge flows steadily around a loop
  • Made by a battery, a generator or a solar panel
  • Keeps going as long as the circuit is complete
  • Powers lights, toys, phones and dough circuits

Where does electricity come from?

  • Batteries turn stored chemical energy into electricity. The 4 AA batteries in a battery holder add up to 6 volts. See How Do Batteries Work?
  • Power plants spin generators with steam, wind or falling water. Spinning magnets near coils of wire push electrons along.
  • Solar panels turn sunlight straight into electricity.

The electricity from power plants travels to homes and schools along power lines. Read how that works in The Electrical Grid.

Batteries give direct current (DC), which flows one way around the loop. Wall outlets give alternating current (AC), which switches direction back and forth, 60 times every second in the United States.

Try it with dough

See electricity at work

You cannot see electricity itself, but you can see what it does. Build one circuit and swap the part at the end to turn the same energy into light and then sound.

You need

  • Battery holder with 4 AA batteries
  • Conductive (salty) play dough
  • 1 LED
  • 1 buzzer

Steps

  1. Roll two pieces of conductive dough and set them on the table about a finger-width apart.
  2. Push the red wire from the battery holder into one piece and the black wire into the other.
  3. Push the long leg of the LED into the dough with the red wire and the short leg into the other piece.
  4. Switch the battery holder on. The LED changes electrical energy into light.
  5. Switch the battery holder off and take out the LED.
  6. Push the buzzer's red wire into the dough with the red battery wire and its black wire into the other piece. Switch it on and listen.
A battery holder wired to a ball of blue dough and a ball of red dough, with an LED glowing across the gap between them
Two pieces of conductive dough with an LED bridging the gap.

What happens

The LED glows and the buzzer beeps, because electricity is carrying energy from the battery through the dough to each part. Switch the battery holder off and both stop, because the loop is broken.

Not working?

Nothing happens? Make sure the two pieces of dough are not touching and the long LED leg (or the buzzer's red wire) is on the red-wire side. See What Is Polarity? for why direction matters.

Electricity safety

Do

  • Use battery-powered kits for experiments
  • Keep water away from anything plugged into the wall
  • Pull plugs out by the plug, not the cord
  • Ask an adult before using anything that plugs in

Don't

  • Never put anything into a wall outlet
  • Never touch power lines or climb near them
  • Never use cords that are frayed or damaged
  • Never experiment with household wiring

Key words

Atom
The tiny building block that everything is made of.
Electron
A tiny particle with a negative charge. Moving electrons carry electricity in metal wires.
Ion
An atom or group of atoms with an electric charge. Ions carry electricity through salty dough and salt water.
Electric charge
A property of particles that makes them push or pull on each other. It can be positive or negative.
Electric current
The flow of electric charge around a circuit.
Static electricity
Electric charge that builds up in one place instead of flowing.
Direct current (DC)
Current that flows one way, like from a battery.
Alternating current (AC)
Current that switches direction back and forth, like from a wall outlet.

For teachers

In metal wires, current is carried by electrons. In conductive dough, it is carried by ions from the dissolved salt, both positive and negative, moving in opposite directions. Our diagrams show conventional current, flowing from the red (positive) side to the black (negative) side, which is the direction used in most textbooks.

A common misconception is that electrons race around the circuit. They actually drift very slowly, often less than a millimeter per second. The LED lights instantly because the push travels through the whole loop at once, like water in a pipe that is already full.

This activity supports NGSS 4-PS3-2: energy can be transferred from place to place by electric currents. Find free lesson plans on our education page.

Electricity questions

What is electricity in simple words?

Electricity is energy carried by moving electric charges, like electrons. When the charges flow around a complete loop, they can light a bulb, ring a buzzer or spin a motor.

What is electricity made of?

Electricity is not a thing on its own. It is the movement of charged particles that are already inside materials. In wires, those particles are electrons. In salty water and salty play dough, they are charged bits of salt called ions.

What are the two types of electricity?

Static electricity is charge that builds up in one place, like on a rubbed balloon, and lets go as a spark. Current electricity is charge flowing steadily around a circuit, like the electricity from a battery.

Who discovered electricity?

No single person discovered electricity. People noticed static electricity thousands of years ago. Benjamin Franklin showed in the 1750s that lightning is electricity, Alessandro Volta built the first battery in 1800, and Michael Faraday worked out how to make electricity with magnets in the 1830s.

How does electricity get to my house?

Power plants make electricity with generators, wind turbines or solar panels. It travels along high-voltage power lines, then through transformers that lower the voltage, and finally into the wires in your walls. Read more in The Electrical Grid.

Is it safe for kids to experiment with electricity?

Battery-powered kits like a dough circuit with 4 AA batteries (6 volts) are a safe way to explore. They are designed for ages 8 and up, and younger kids can join in with an adult. Wall outlets and household wiring carry far more power and are never safe for experiments.

Printable guide: Circuits Explained (PDF)

Next, try a project

Build the Circuit Project A free step-by-step project with printable instructions.

Keep learning