12/12/2013
 Have
you ever pulled a sweater over your
head and felt your hair standing up?
 Have
you ever touched a door knob or a car
door handle and got an electric shock?
 Have
you ever rubbed your head against a
balloon?
 What
is going on here??
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12/12/2013

These examples are called electric charges

Electric charges are charged particles that exert
a force on each other

These particles are very small in fact there are
millions of them on each strand of your hair as
you pull the hat off

Electric charges cause your hair to repel each
other and attract to the balloon

Water and ice move around inside the cloud; forced
up by warm air currents, down by gravity, and
compressed in the cloud. Just as rubbing a balloon
can create static electricity, the particles in the
cloud become charged. Positive charges move up,
and negatives move down.
Once a significant charge separation has built up, the
positive and negative charges seek to reach each
other an neutralise. ‘Streamers’ come up from the
ground to form a pathway. Once a pathway is
completed a spark forms, neutralizing the charge.
As the negative charge races down, the air
surrounding it heats up.The spark is very hot at
almost 20,000 degrees Celsius, and it rapidly heats
the air to create a shock wave.


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12/12/2013
 Considering
light travels very fast – about 300
million metres per second, and that sound
only travels at 300 metres per second; light
is a million times faster than the sound
produced. To find out how far away the
storm is, you can count how long you hear
the sound after the lightning. For every 4
seconds between the flash and the rumble,
the thunderstorm is 1 mile away

The electron charge that builds up on surfaces of
objects is called the static electric charge
 Negatively
charged particles have more
electrons then protons and Positively
charged particles have more protons
then electrons.
 Recall
atoms
 Draw
these ones: oxygen, sodium,
carbon
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 Friction-
when objects rub together the force
can cause them to transfer from one to the
other
 Electron
affinity- the tendency of a
substance to hold on to its electrons
 All
substances have different electron
affinitys some tend to lose electrons and
some tend to gain electrons.
 Copy
out chart on page 208 of the substances
and their ability of gaining or losing electrons
also called Triboelectric Series
 Answer
the learning checkpoint question on
Page 209 # 1-5
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 Particles
with opposite charges attract to
each other
 Particles
with like charges repel each other
Conductors are made of materials that
electricity can flow through easily.
 These materials are made up of atoms whose
electrons can move away freely.
Some examples of conductors are:
 Copper
 Aluminum
 Platinum
 Gold
 Silver
 Water
 People and Animals
 Trees

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12/12/2013
 Insulators
are materials opposite of
conductors. The atoms are not easily freed
and are stable, preventing or blocking the
flow of electricity.
Some examples of insulators are:
 Glass
 Porcelain
 Plastic
 Rubber

Electricity will always take the shortest path to
the ground. Your body is 60% water and that
makes you a good conductor of electricity. If a
power line has fallen on a tree and you touch the
tree you become the path or conductor to the
ground and could get electrocuted.

The rubber or plastic on an electrical cord
provides an insulator for the wires. By covering
the wires, the electricity cannot go through the
rubber and is forced to follow the path on the
aluminum or copper wires.

Water is a fair conductor and when electrical
charges are near water you can get injured and
electrocuted.
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Copy
chart in the text book page
210 and answer questions 1-6 on
page 211.
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