Electric Charge
Charge is a property of matter; like charges repel and unlike attract.
About this topic
Electric charge is a basic property of matter, coming in two kinds, positive and negative. Like charges repel and unlike charges attract. Charge is measured in coulombs; a proton carries +1.6 × 10⁻¹⁹ C and an electron the same amount negative. Everything from chemistry to nerve signals ultimately depends on these tiny charges and the forces between them.
Charge is quantised, coming in multiples of this unit, and conserved: it is never created or destroyed, only moved. Most objects are neutral because positive and negative charges balance, and electricity is the story of what happens when they don't. When you rub a balloon on your hair, electrons hop from one surface to the other, leaving the balloon with a slight excess of negative charge and your hair with a matching deficit.
A single coulomb is a huge amount, about 6 × 10¹⁸ electrons, so everyday static charges are measured in microcoulombs or nanocoulombs. Charge underlies lightning, batteries, computer chips and the very structure of atoms.
A common misconception is that positive charges move through wires; in solids it is almost always the negative electrons that move. Another is that a neutral object has no charges at all, when in fact it has equal amounts of both.
Key ideas
- Protons positive, electrons negative
- Charge is conserved
- Unit: coulomb
Quick check
Use cases: where Electric Charge helps
- Homework: review the key idea behind Electric Charge before you start a problem set.
- Exam revision: use the quick check to test whether you can recall Electric Charge without notes.
- Visual learning: play with the interactive lab to see how Electric Charge changes when you adjust its inputs.
- Teaching a friend: explain Electric Charge in your own words, then compare your version with the key ideas.
The same laws describe car crashes, sports, satellites and everyday machines.
Frequently asked questions
What is Electric Charge?
Charge is a property of matter; like charges repel and unlike attract.
What will I learn in Electric Charge?
Protons positive, electrons negative. Charge is conserved. Unit: coulomb.
Is Electric Charge part of Physics?
Yes. It is one of 150 Physics topics on LearnViz HighSchoolEdu, with 3 key ideas, a live animation and a quick check.
Does the Electric Charge lab work on a phone or tablet?
Yes. The animation resizes to fit your screen and supports touch, so you can drag, tap and slide with your finger.
How should I study Electric Charge?
Read the summary and key ideas first, play with the interactive lab to see the idea in motion, then answer the quick check. If you get a question wrong, go back to the key idea it tests.
Do I need an account, and is my progress saved?
No account is needed. Marking a topic as learned is saved in your own browser, so it stays on that device and is not sent to a server.