Sunday, August 30, 2009

The Shocking Story of Electricity

Hey kids, have you ever watched lightning in the sky at night, or gotten zapped when you touched a metal door? Those are two shocking examples of electricity!

Elementary science teaches us that everything in the world is made up of tiny particles called atoms. An atom is made up of a hard core, called a nucleus, and a cloud of fast whizzing particles called electrons that move around the nucleus. Sometimes electrons can even jump from one place to another. When electrons move, this creates a current of electricity.

When you see lightning up in the sky, you're actually seeing billions of electrons jumping all at once from one place to another. Moving electrons tend to release a lot of energy, and we can use this electricity to do all kinds of things, from powering a computer to splitting an atom apart.

Our bodies also use electricity. Every thought that you have is the result of tiny electrical signals jumping between the cells in your brain. Everything that you feel is an electrical message passed down long pathways called nerves that run from your body to your brain. Even your heart is controlled by electrical signals that tell each cell in your heart when to beat.

A heart attack happens when this electrical signal gets mixed up and every cell in your heart tries to beat at a different time. That's why doctors can use a machine called a defibrillator to deliver a powerful electric shock to your heart - it resets all the heart cells and gets them beating in time again!

Here's a fun and easy elementary science experiment you can do to see electricity at home:

A Hair-Raising Experiment

1. Blow up a balloon and tie a knot in the end to keep the air from escaping.
2. Rub the balloon quickly back and forth over your head for ten seconds.
3. Slowly pull the balloon away. Watch what happens to your hair.
4. Touch the balloon to a smooth surface, like a wall, and let go. If you rubbed enough, it should stick!

What's Happening:

Have you ever heard the saying "opposites attract"? Well, that's true of electric charges, too. Electrons have a negative charge, and the protons that make up the nucleus of an atom have a positive charge. Electrons push away from other electrons, but are strongly attracted to things with a positive charge. There are usually the same number of protons and electrons in an atom, so most of the time, they cancel each other out.

When you rub the balloon over your hair, the balloon grabs electrons from the atoms in your hair. Now there are more electrons than protons in the balloon, and fewer electrons than protons in your hair. This leaves the balloon with a negative charge and your hair with a positive charge. Since opposites attract, the negatively charged balloon sticks to your positively charged hair!

When you touch the balloon to the wall, the electrons in the atoms of the wall are repelled by the balloon and move away from it, but the protons in the wall are attracted to the electrons in the balloon and move slightly toward it. The negative charge in the balloon is attracted to the positive charge in the wall, and zap! It sticks just like a magnet.

Now that is shocking science!



Article Source: http://EzineArticles.com/?expert=Sarah_Jane_Elliott

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