Unit 8 Part 2- Electric Charge & Static Electricity

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Section 2: Electric Charge & Static Electricity

Multiple Choice

Magnetic field lines around a bar magnet

• are only perpendicular to the magnet.

• spread out from one pole and curve around to the other.

• cross back and forth over one another.

• are perfectly straight.

Multiple Choice

True or False: A magnet is attracting when it pushes objects away from each other.

• True

• False

Multiple Choice

Which way will the magnets move after they are released?

• Towards each other
• Away from each other
• Not enough information
• Up

• Down

Multiple Choice

What is responsible for the Magnetic Field around Earth?

• The Sun

• The Earth's core

• The Earth's crust

• The Earth's mantle

Multiple Choice

Every magnet, regardless of its shape, has two

• magnetic poles.

• magnetic fields.

• magnetic charges.

• magnetic needles.

Multiple Choice

What does this picture represent?

• Magnetic forces between like poles

• Magnetic forces between opposite poles

• Magnetic forces between two metals

Multiple Choice

As Earth’s magnetic poles move, the magnetic declination in a given location will

• stay the same.

• switch to point south.

• change.

• return to zero.

Hotspot

At which point is the magnetic field the strongest?

Lesson Objectives

• Define an Electric Charge

• Describe an Electric Field

• Explain how Electric Charges and Fields interact

• Describe Static Electricity

  • How it Builds up

  • How it is transferred

Types of Charges

• All atoms contain small particles called Electrons and Protons

  • Electrons have a Negative Charge

  • Protons have a Positive Charge

• Charges always interact the same way

  • Similar charges repel each other

  • Opposite Charges Attract each other

What is Electric Force?

• Electricity: the interaction between electric charges

• Electric Force: The force that occurs between charged objects

  • Can act at a distance

Electric Fields

• Electric Field: The region around an object where an object's electric force is exerted on other charged objects

  • Is invisible

  • Gets weaker the farther away from the charge

Electric Field Lines

• Just like with magnets, an electric field can be mapped out using lines

  • Lines are drawn to show how a positive charge would act

    • Repelled away from positive charges and toward negative charges

  • Adding more charges adds more lines because each charge exerts a force

Multiple Choice

Atoms contain charged particles called

• Protons and Electrons

• Protons, Electrons, and Neutrons

• Protons and Neutrons

• Electrons and Neutrons

Drag and Drop

Charges that are different ​ ​

Placeholder

each other.

Drag these tiles and drop them in the correct blank above

attract

repel

cancel out

multiply

divide

How does Charge Build up?

• Most objects have no overall charge

  • Has the same number of Protons and Electrons

  • Neutral

• An object can become charged by gaining or losing electrons

  • If an object loses electrons, it becomes more positively charged

  • If an object gains electrons, it becomes more negatively charged

How does Charge Build up?

• Static Electricity: the build-up of charge on an object

  • Charges do not flow continuously but slowly collect in an object

Drag and Drop

The Balloon in this picture has a ​

Placeholder

charge, because it has ​

Placeholder

protons and electrons.​

Drag these tiles and drop them in the correct blank above

neutral

equal

positive

negative

more

less

no

magnetic

Drag and Drop

Rubbing the balloon on the sweater allows more electrons to move onto the balloon. This gives the balloon a ​

Placeholder

charge.

Drag these tiles and drop them in the correct blank above

negative

positive

neutral

powerful

Drag and Drop

The ​

Placeholder

charges in the girl's hair are attracted to the negative charge in the balloon.

Drag these tiles and drop them in the correct blank above

positive

negative

neutral

static

Multiple Choice

In Static Electricity, charges

• flow continuously

• flow intermittently

• build up in an atom

• build up on an object

Charging Objects

• Law of Conservation of Charge: Charges are not created nor destroyed, only transferred from one object to another

• There are four ways an object can gain or lose charge

  • Friction

  • Conduction

  • Induction

  • Polarization

Charging By Friction

• Involves two uncharged objects rubbing against each other

  • As the objects are moved, electrons can be moved from one object to another

Charging By Conduction

• Electrons are transferred from a charged object to another object through direct touching

  • Electrons move toward an area with a more positive charge

Charging By Induction

• Electrons can react to the electric field of a charged object without touching the object itself

• Metals tend to lose electrons very easily

• Induction: When the electrons in a metal object react to an electrical field, and make an object have a positive and a negative end

  • Can produce a spark

Charging By Polarization

• Sometimes Electrons do not move between atoms, but rotate in their atoms

  • Electrons move so they are on one end of an atom

• Polarization: The process of individual atoms gaining a positive and negative charge on their ends

  • Does not involve transfer between objects

  • Overall the object remains neutral

Multiple Choice

A region around a charged object where the object's electrical force is exerted on other charged objects is an electrin

• field

• outlet

• socket

• power plant

Match

Match the following methods of charging to their description

• Friction

• Conduction

• Induction

• Polarization

Electrons are transferred through the rubbing of two uncharged

Electrons are transferred from a charged obect to another through contact

Electrons move within a charged object to create a positive and negative end

Electrons move in an atom to give it a positive and negative end

• Electrons are transferred through the rubbing of two uncharged

• Electrons are transferred from a charged obect to another through contact

• Electrons move within a charged object to create a positive and negative end

• Electrons move in an atom to give it a positive and negative end

Static Discharge

• Once charged, an object will slowly change to become neutral

  • Negatively charged objects will lose electrons

  • Positively charged objects will gain electrons

• Static Discharge: The loss of Static Electricity as electric charges transfer from one object to another

  • Often produces a spark from electrons heating the air

  • More common in dry weather because water is not in the air to attract charges

Static Discharge

• Lighting is static discharge in action

  • During storms, air particles move inside clouds and become charged

  • As the electrons move from areas that are negatively charged to areas that are positively charged, they produce a spark

  • When charges form a negative electric field, the Earth becomes more positively charged, which can allow lightning to jump from clouds to the Earth's surface

Multiple Choice

Most objects have some overall charge

• True

• False

Multiple Choice

The buildup of charges on an object is called

• static discharge.

• static electricity

• positive charge.

• negative charge

Open Ended

People who work with computers have to be careful about static discharge because even a small shock can damage a computer board. What are two things a person can do to avoid static discharge from occurring? Explain how each one would change the amount of discharge.