Electric charge facts for kids
Electric charge is a basic property found in tiny parts of atoms, like electrons and protons. Electrons have a negative charge, and protons have a positive charge.
Imagine magnets! Things with opposite charges (like a negative electron and a positive proton) pull towards each other. This is called attraction. It's why electrons and protons stick together to make atoms. But things with the same charge (like two negative electrons or two positive protons) push each other away. This is called repulsion. This idea is known as the Law of Charges. A scientist named Charles-Augustin de Coulomb discovered it. The strength of this pulling and pushing is explained by Coulomb's Law.
When an object has the same number of electrons and protons, it has no overall charge. We call it neutral. If an object has more electrons than protons, it becomes negatively charged. If it has fewer electrons than protons, it becomes positively charged.
Opposite charges attract, and like charges repel. If a negatively charged object and a positively charged object meet, electrons might move from the one with too many to the one with too few. When electrons move from one place to another, it creates an electrical current.
What is Static Electricity?
Have you ever shuffled your feet on a carpet and then touched a doorknob, getting a small shock? That's static electricity! When you walk on the carpet, your body can gain extra electrons, making you negatively charged. The doorknob is neutral.
When you get close to the doorknob, the extra electrons on your body want to jump to the doorknob. If there are enough electrons, they can jump across the small gap. This jump creates a tiny spark and a shock. The length of the spark shows the voltage, which is like "electrical pressure." The number of electrons moving per second is called amperage, or the "rate of electron flow."
If you get a strong static charge, it might even make your hair stand on end! This happens because each hair gets the same charge, and since like charges repel, they push away from each other.
The static shock you get from a doorknob is usually around 25,000 to 30,000 volts. But don't worry, the electric current only flows for a very short time. So, it doesn't usually cause any harm.
However, lightning is a much bigger example of electric charge. Clouds can build up huge electrical charges, with much higher voltages and amperage. This means a massive number of electrons can jump from a cloud to the ground (or vice versa). If lightning strikes a person, the electric shock can be very dangerous and even deadly.
How Charges Are Made
Scientists like James Clerk Maxwell studied how objects become charged. In 1873, he described a simple experiment. Normally, things like glass and resin (a type of plastic) are neutral. But if you rub them together, they can become charged and attract each other.
Imagine you rub a piece of glass with a piece of resin. Then, you do the same with a second set of glass and resin. Here's what you would see:
- The two pieces of glass would push each other away (repel).
- Each piece of glass would pull towards each piece of resin (attract).
- The two pieces of resin would push each other away (repel).
When objects can attract or repel other things this way, we say they are 'electrified' or 'charged with electricity'.
An electrical charge is created when two different materials are rubbed together. This happens because one material gives electrons to the other. Atoms in different materials have different strengths in holding onto their electrons. So, the material that attracts electrons more strongly will take them from the other material. For example, if glass is rubbed against something else, it might gain or lose electrons. It depends on what the other material is.
Scientists decided to call things that have gained electrons "negatively charged." Things that have given up electrons are called "positively charged." These names were just a random choice or an agreement (convention) made a long time ago.
Besides rubbing, objects can become charged in many other ways too!
Images for kids
-
Coulomb's torsion balance was used to study electric forces.
See also
In Spanish: Carga eléctrica para niños
