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Electricity
Electricity: The Mysterious Force
What exactly is the mysterious force we call electricity? It is simply moving electrons. And what exactly are electrons? They are tiny particles found in atoms.
Everything in the universe is made of atoms—every star, every tree, every animal. The human body is made of atoms. Air and water are, too. Atoms are the building blocks of the universe. Atoms are so small that millions of them would fit on the head of a pin.

Atoms are made of even smaller particles. The center of an atom is called the nucleus. It is made of particles called protons and neutrons. The protons and neutrons are very small, but electrons are much, much smaller. Electrons spin around the nucleus in energy levels a great distance from the nucleus. If the nucleus were the size of a tennis ball, the atom would be the size of the Empire State Building. Atoms are mostly empty space.

Electrons usually remain a relatively constant distance from the nucleus in well defined regions called energy levels. The level closest to the nucleus can hold two electrons. The next level can hold up to eight. The outer levels can hold even more, but the outermost level can hold no more than eight. Some atoms with many protons can have as many as seven levels with electrons in them.

CARBON ATOM

If you could see an atom, it would look a little like a tiny center of balls surrounded by giant invisible clouds (energy levels). The electrons would be on the surface of the clouds, constantly spinning and moving to stay as far away from each other as possible. Electrons are held in their levels by an electrical force.

The protons and electrons of an atom are attracted to each other. They both carry an electrical charge. An electrical charge is a force within the particle. Protons have a positive charge (+) and electrons have a negative charge (-). The positive charge of the protons is equal to the negative charge of the electrons. Opposite charges attract each other. When an atom is in balance, it has an equal number of protons and electrons. Neutrons carry no charge, and their number can vary. The number of protons in an atom determines the kind of atom, or element, it is. An element is a substance in which all of the atoms are identical. Every atom of hydrogen, for example, has one proton and one electron, with no neutrons. Every atom of carbon has six protons, six electrons, and six neutrons. The number of protons determines which element it is.

SEVERAL COMMON ELEMENTS
ELEMENT
Hydrogen
Lithium
Carbon
Nitrogen
Oxygen
Magnesium
Copper
Silver
Gold
Uranium

32

SYMBOL
H
Li
C
N
O
Mg
Cu
Ag
Au
U

PROTONS
1
3
6
7
8
12
29
47
79
92

ELECTRONS
1
3
6
7
8
12
29
47
79
92

NEUTRONS
0
4
6
7
8
12
34
51
118
146
Intermediate Energy Infobook

The electrons in the levels closest to the nucleus have a strong force of attraction to the protons. Sometimes, the electrons in the outermost levels do not. These electrons can be pushed out of their orbits. Applying a force can make them move from one atom to another. These moving electrons are electricity.

BAR MAGNET

Magnets
In most objects, the molecules are arranged randomly. They are scattered evenly throughout the object.
Magnets are different—they are made of molecules that have north-and south-seeking poles. Each molecule is really a tiny magnet. The molecules in a magnet are arranged so that most of the north-seeking poles point in one direction and most of the south-seeking poles point in the other. This creates a magnetic field around the magnet.

This creates an imbalance in the forces between the ends of a magnet. This creates a magnetic field around a magnet. A magnet is labelled with north (N) and south (S) poles. The magnetic force in a magnet flows from the north pole to the south pole.

LIKE POLES

Have you ever held two magnets close to each other? They don’t act like most objects. If you try to push the...
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