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Electronvolt facts for kids

Kids Encyclopedia Facts

The electron-volt, or eV for short, is a special unit used to measure tiny amounts of energy. Imagine a tiny particle called an electron. If this electron gets pushed by 1 volt of electricity, the energy it gains is exactly one electron-volt.

We often use Joules to measure energy, like how much energy is in a candy bar. But for super small things, like the energy inside an atom or carried by a single subatomic particle, joules are too big. That's where electron-volts come in handy! They help scientists talk about these tiny energies more easily.

To change joules into electron-volts, you divide the joule amount by the charge of an electron. This charge is a very small number: about 1.602×10−19 coulomb.

For example, 5 joules is the same as 3.125×1019 electron-volts. That's a huge number of electron-volts for just 5 joules! This shows how small an electron-volt really is.

Why We Use Electron-Volts

Electron-volts are super important in areas of science that study the smallest parts of matter.

Studying Atoms and Particles

Scientists use electron-volts a lot in atomic physics, which looks at atoms and their parts. They also use them in nuclear physics, which studies the center of atoms (the nucleus), and in particle physics, which explores even smaller particles than atoms.

Measuring Light Energy

One cool way electron-volts are used is to measure the energy of photons. Photons are tiny packets of light energy. Scientists can figure out a photon's energy by seeing how much voltage is needed to make it release an electron from a material. This is called the photoelectric effect. It's like measuring how much "push" a light particle has.


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See also

Kids robot.svg In Spanish: Electronvoltio para niños

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