Electricity objectives

Static The word “static” means stationary or not moving. When an object becomes charged by a rubbing process (friction), it is said to possess a static charge.

Static Electricity Refers to electric charges that can be collected and held in one place. It is the temporary transfer of electrons.

Bill Nye: Static Electricity

Charges on Objects….. Remember: 1.Protons have a positive charge 2.Electrons have a negative charge

3. When the number of protons equals the number of electrons, the atom is neutral.

Neutral Atom

When an atom or material becomes charged, it is because electrons transfer into or out of the atom or material. Static Electricity: Snap, Crackle, Jump | Science | Classroom Resources | PBS LearningMedia

Insulator A material that does not allow electric charges to move easily. Examples: Glass, plastics, wood, rubber, etc

Conductor Is a material in which electric charges can move more easily. Example: metals

Since static electricity is charge that is held fixed in one place, only insulators can retain a static charge. Conductors such as copper and aluminum allow charge to flow.

Insulator – Conductor Video Clips https://www.youtube.com/watch?v=ZgDIX2GOaxQ (watch first 7 mins) https://www.youtube.com/watch?v=3kyntGqT14s https://www.youtube.com/watch?v=qUhxmXZwPmg

Changing the Charge of an Atom The movement, or transfer of electrons from one atom to another changes the charge on the atom. When an atom loses electrons, the atom becomes positively charged. When an atom gains electrons, the atom becomes negatively charged.

If electrons are removed from a neutral object, the object will become positively charged. If electrons are added to a neutral object, the object will become negatively charged

How can a positively or negatively charged object become neutral?

Activity 7-1B Visualizing Charge Transfer Pg. 231

Text Questions Page 237 # 1-19 Electroscope Demo Video Clip (Question # 12)

Electric Discharge The removal of electric charge from an object. •Ex. Lightening “shocks”

Video Clip: Charging and Discharging https://www.youtube.com/watch?v=crOmf6z1M40

The Coulomb (C) •The unit of electric charge. •It takes the addition or removal of 6.25 x 1018 electrons to produce 1C of charge.

Laws of Electric Charges: 1. Like charges repel 2. Unlike charges attract 3. Charged objects attract some neutral ones.

Balloon Example When you rub a balloon in your hair, the balloon becomes negatively charged. Since the balloon is an insulator, the negative charge remains in a nearly fixed location on the balloon. If you place the charged balloon against the wall, the negative charges in the wall are repelled away from the balloon. The part of the wall closest to the balloon now has a positive charge The negative charge on the balloon will be attracted to the positive wall and therefore the balloon will stick

Static Electricity and Water - YouTube

Technologies and Static Electricity Lightning Rods

A lightening rod is a conductor that is placed on top of a building A lightening rod is a conductor that is placed on top of a building. If lightening occurs near the building, the large amount of charge will pass through the lightening rod to the ground rather than the building. Allowing charge to flow into Earth’s surface is called Grounding.

Photocopier (Page 241)

Electrostatic air cleaner

The ionizers remove electrons from particles in the air, and the charged particles are then attracted to a plate on the device.

Text Questions Page 246-247 Chapter 7 Review