8.3.1-Electric Charge & Electric Forces

Multiple Choice

What is an ion?

• A Charged Atom
• A Large Atom
• A Small Atom
• A Cute Atom

Multiple Choice

Cations are...

• Positive
• Negative
• Neutral
• Purring

Multiple Choice

Anions are...

• Positive
• Negative
• Neutral
• Crying

Multiple Choice

An atom becomes _________ when it gains electrons.

• Positive
• Negative
• Neutral
• Invinsible

Multiple Choice

An atom becomes _______ when it loses electrons.

• Positive
• Negative
• Neutral
• Invinsible

Multiple Choice

How would you write a Sulfur that has gained 2 electrons?

• S⁺²

• S^-2

• S⁺⁶

• S^-6

Multiple Choice

A Bromine ion gains 1 electron, which of the following is the correct symbol for a Bromine ion?

• Br^-1

• Br⁺¹

• Br⁺⁷

• Br^-7

Multiple Choice

) When an object has more negative charge than positive charge, the object is called _____.

• A) electric discharge

• B) magnetic domain

• C) electric field

• D) electrically charged

Multiple Choice

An object with equal amounts of positive and negative charge is electrically _____.

• A) charged

• B) negative

• C) neutral

• D) positive

Static Electricity

• Electrons are a part of atoms (makes up stuff) that can move

• The sudden movement of charges is the ZAP you feel

• The build up of electric charges (electrons) causes objects to produce a force

Charged objects

• When an objects gains electrons, it becomes more negative

• When an object loses electrons, it becomes more positive

• If an object has the same amount of positive charges as negative charges, then it will be neutral

Charged objects

Objects may pick up electrons to become negative, or lose electrons to become positive. Or, if they have an equal amount of + and -, they are neutral

Multiple Choice

If an object gains electrons, it will be...

• positively charged

• negatively charged

• neutral

Interactions between charges

• Charges that are like (both positive, or both negative) will repel - or move away from each other.

• Charges that are different will attract, or move near each other

Multiple Choice

Two objects that are both positively charged will

• attract each other

• repel each other

• do nothing

Multiple Choice

Two objects that have opposite charges (one positive, one negative) will

• attract each other

• repel each other

• do nothing

Multiple Choice

What type of charge does this balloon have?

• postive

• negative

• neutral

Electrical Conductors, Insulators,

and Ways to Charge

Moving Charges

Have you ever noticed that electrical cords are often made from metal and plastic? Different materials are used because electric charges move through some materials more easily than they move through others. Most materials are either conductors or insulators based on home easily charges move in them.

Electrical Conductors

An electrical conductor is a material in which charges can move easily. Most metals are good conductors because their electrons are free to move. Conductors are used to make wires. Copper, aluminum, and mercury are good conductors.

Electrical Insulators

An electrical insulator is a material in which charges cannot move easily. Insulators do not conduct charges very well because their electrons cannot flow freely. Insulation around wires are made of insulators. Plastic, rubber, glass, wood, and air are good insulators.

Multiple Choice

What is the difference between insulators and conductors?

• Insulators allow electricity to flow easily and conductors do not.

• Conductors allow electricity to flow easily and insulators do not.

• Conductors are used only for electricity and insulators are used only for heat.

• Insulators are used only for electricity and conductors are used only for heat.

Multiple Select

Select the conductors.

• copper

• wood

• air

• mercury

• rubber

Multiple Select

Select the insulators.

• aluminum

• plastic

• glass

• steel

• diamond

Copy this chart onto page 94 of your notebook.

Friction

Charging by friction happens when electrons are "wiped" from one object to another. If you use a cloth to rub a plastic ruler, electrons move from the cloth to the ruler. The ruler gains electrons and becomes negatively charged. At the same time, the cloth loses electrons and becomes positively charged.

Conduction

Charging by conduction happens when electrons move from one object to another by direct contact. Suppose you touch an uncharged piece of metal with a positively charged glass rod. Electrons from the metal will move to the glass rod. The metal loses electrons and becomes positively charged.

Induction

Charging by induction happens when charges in an uncharged metal object are rearranged without direct contact with a charged object. Suppose you hold a metal object near a positively charged object. The electrons in the metal are attracted to and move toward the positively charged object. This movement induces an area of negative charge on the surface of the metal.

Find this worksheet. It is with your extra pages for unit 2.

These are not in the correct order. Label each one with an "I" for induction, a "C" for conduction, or a "F" for friction.

(you could also choose to color code them instead)

Check your answers!

Cut and glue these notes onto

page 95 in your notebook.

Multiple Select

Select the two that are true.

• Insulators are usually charged by friction.

• Conductors are usually charged by friction.

• Insulators are usually charged by conduction and induction.

• Conductors are usually charged by induction and conduction.

• Conduction, induction, and friction are used to charge both conductors and insulators.

Multiple Choice

What do we call it when two objects rub together?

• friction

• conduction

• induction

• electroscope

Multiple Choice

What is it called when a charged object induces a charge onto a neutral object without direct contact?

• friction

• conduction

• induction

• electroscope

Multiple Choice

What is it called when electrons are transferred by direct contact?

• friction

• conduction

• induction

• electroscope

Multiple Choice

What causes the electric discharge between the body and the sweater?

• Magnetic field

• Chemical reaction

• Exchange of electrons during friction

• Static electricity

Multiple Choice

What form of energy is released during the electric discharge?

• Electrical energy

• Thermal energy

• Kinetic energy

• Potential energy

Multiple Choice

What is the result of the energy release during the electric discharge?

• Emission of magnetic and gravitational waves

• Production of water and air

• Creation of solid and liquid

• Production of light, heat, and sound

Multiple Choice

Why does a crackling sound occur during the electric discharge?

• Rapid expansion and contraction of air

• Friction between two surfaces

• Static electricity buildup

• Presence of water vapor in the air

Multiple Choice

What is the role of friction in the electric discharge?

• Reducing static electricity

• Preventing the generation of electricity

• Generating static electricity

• Attracting electricity from the environment

Multiple Choice

How does the electric discharge between the body and the sweater occur?

• The electric discharge occurs due to the heat generated between the body and the sweater.

• Electrons are transferred from one to the other, causing an imbalance of charge and resulting in an electric discharge.

• Protons are transferred from one to the other, causing an imbalance of charge and resulting in an electric discharge.

• The body and the sweater repel each other, causing an electric discharge.

Multiple Choice

What happens to the energy released during the electric discharge?

• It is converted into mechanical energy

• It is absorbed by the surrounding materials

• It disappears without any effect

• It is released in the form of light, heat, and sound.

Multiple Choice

What is the significance of the crackling sound during the electric discharge?

• The crackling sound is caused by the rapid expansion and contraction of air due to the heat produced by the electric current.

• The crackling sound is a sign of impending thunderstorm

• The crackling sound is a result of the electric current being too weak

• The crackling sound is caused by the presence of tiny insects in the air