Electricity is related to charges, and both electrons (-) and protons (+) carry a charge. Electricity is related to charges, and both electrons (-) and

Electricity is related to charges, and both electrons (-) and protons (+) carry a charge.

Copyright © 2010 Ryan P. Murphy

Quick Atom Review:• When an atom becomes charged it is

called an ion


• Electrons are negatively charged


• Electrons are negatively charged• Protons (nucleus) are positively charged






• Electrons are negatively charged• Protons (nucleus) are positively charged• Their charges are about equal


• Electrons are negatively charged• Protons (nucleus) are positively charged• Add Electrons – Atom becomes more

negatively charged.


• Electrons are negatively charged• Protons (nucleus) are positively charged• Take away (strip) electrons then the atom

becomes more positively charged.


• Annoying Tape.– Teacher gives each student 2 long pieces (10

centimeters each) strips of clear tape. • Make non-stick handles by folding a small amount

tape on itself.




tape on itself.

– Stick one piece of tape to table. – Stick the other piece of tape on that tape.– Quickly pull tape from table and then apart.– Observe what happens to the tape when it gets

close to each other and then eventually your arm.• Try and dispose of in trash barrel by shaking the tape

from your hand and not picking. Copyright © 2010 Ryan P. Murphy



tape on itself.

– Stick one piece of tape to table. – Stick the other piece of tape on that tape.– Quickly pull tape from table and then apart.– Observe what happens to the tape when it gets

close to each other and then eventually your arm.


• What happened!

• What happened!– When you removed the tape from the table you

gave it an electrical charge. When you peeled the tape apart from each other, one piece of tape gained more of a charge than the other.

• What happened!– When you removed the tape from the table you

gave it an electrical charge. When you peeled the tape apart from each other, one piece of tape gained more of a charge than the other.• Opposite charges attract (+) (-)



tape on itself.

– Stick both pieces of tape to table. – Quickly pull tape from table.– Observe what happens to the tape when it gets


from your hand and not picking.




tape on itself.

– Stick both pieces of tape to table. – Quickly pull tape from table.– Observe what happens to the tape when it gets


from your hand and not picking.


• What happened?

• What happened? – Each piece of tape gained a negative charge

when removed from the table. When they were brought close together they moved away from each other.

• What happened? – Each piece of tape gained a negative charge

when removed from the table. When they were brought close together they moved away from each other.• Like charges repel. (-) (-)

Electrostatic Charges!• Life occurs because of electrostatic charges.

• Life occurs because of electrostatic charges.• Without them, life would simply unravel.

• Life occurs because of electrostatic charges.• Without them, life would simply unravel.

Static Electricity: The imbalance of positive and negative charges.


Activity- Bad Hair Day Demonstration!

– Rub balloon all around your head.– Question: Why does this happen?


• Answer!– Electrons from your body move into the balloon.– This gives you a positive charge.– Your hair is also positive.– Like charges repel so hair tries to get away from

body.


• Demonstration - Static Electricity– Observe two balloons without a build up of a

charge.



charge.– Now rub balloons on head / clothes.– How are they behaving now?











Repel




Repel




Repel

Activity! Static Balloons


Activity! Static Balloons– 2 students blow up a balloon and tie it off.– Students rub balloon against hair and quickly stick to

wall (at same time).– Observe what happens….. – Whose balloon will last the longest?


• Answer!

• Answer!– Electrons from hair are removed and put into balloon.

• Answer!– Electrons from hair are removed and put into balloon.– Balloon has slight negative charge.

• Answer!– Electrons from hair are removed and put into balloon.– Balloon has slight negative charge.– The atoms orient and wall has slight positive charge.

• Answer!– Electrons from hair are removed and put into balloon.– Balloon has slight negative charge.– The atoms orient and wall has slight positive charge.– Opposite charges attract and balloon sticks.

• We usually only notice static electricity in the winter when the air is very dry.

• We usually only notice static electricity in the winter when the air is very dry. During the summer, the air is more humid.

• We usually only notice static electricity in the winter when the air is very dry. During the summer, the air is more humid. – The water in the air

helps electrons move off you more quickly, so you can’t build up a large static charge.

• Video! How a Van de Graaff Generator works.– http://www.youtube.com/watch?v=I2G0IdTWGQU

http://www.youtube.com/watch?v=I2G0IdTWGQU

http://www.youtube.com/watch?v=I2G0IdTWGQU

• Video! If you don’t have a Van de Graaff Generator.– http://www.youtube.com/watch?v=hh8PqQDOAb8

http://www.youtube.com/watch?v=hh8PqQDOAb8

Mythbusters: Static Electricity

• https://www.youtube.com/watch?v=uw6-PhvcS3M

https://www.youtube.com/watch?v=uw6-PhvcS3M



Documents

Electricity is related to charges, and both electrons (-) and protons (+) carry a charge. Electricity is related to charges, and both electrons (-) and