Sceince Chapter 7

explain why clothes dried in a clothes dryer clings together more than clothes dried on a clothesline

clothes dried in a clothes dryer spins around, creating friction, therefore the static created makes them cling more while clothes on a clothesline is separated, no static being formed.

grounding

connecting a conductor so that electric charge flows into the ground

to increase the electric force between two charged objects, the distance separating the two charges should be

decreased

examples of electric discharge are

lightening and "shocks"

list 4 technologies that rely on static electricity to function

lighting rods, photocopiers, electrostatic air cleaners, cling wrap, paint pray(automobiles)

two ___ charges are either both negative or both positive

like

insulators

materials do not allow electrons to move freely are called electrical

conductors

materials that allow electrons to move freely are called electrical

examples of conductors are

metals, copper, gold, iron, water

how do you think you would charge a metal object?

mount it to an insulator

electrons have a ______ charge

negative

a negative charged is repelled by a __ charge

negative charge

if a ____ charged balloon is brought near a positively charged rod, the balloon is attracted to the rod

negatively

if a ____ or _____ charged object is brought near a neutral electroscope, the leaves will seperate

negatively and positively

an uncharged state of a particle or object; occurs when the positive charge of the nucleus is exactly balanced by the negative charge of the electrons

neutral

when the number of protons equals the number of electrons, the atom has a ____ charge

neutral

an uncharged particle located in the nucleus of an atom

neutron

static electricity

occurs when an electric charge is collected and held in one place

if two ______ charges are brought together, they will be attracted

opposite

protons have a ____ charge

positive

using your knowledge of the atom, explain why negative charges can be transferred from one object to another, but positive charges cannot

positive charges, protons, are located in the nucleus therefore cannot be transferred. Electrons are moving freely outside the nucleus and can easily be transferred between objects.

a negative object attracts an unknown object. the unknown object could be

positive or neutral

a positively charged particle located in the atomic nucleus

proton

if electrons are _____ from a neutral object, the object will become positively charged

removed

a positive object _____ a positive object

repels

6.25 x 10^8 is about the number of electrons that pass into a 100w light bulb per

second

to decrease the electric force between two charged objects, the amount of charge on one or both objects

should be decreased

to increase the electric force between two charged objects, the amount of charge on one or both objects

should be increased

current electricity

the continuous flow of charge in a complete circuit

the distance between two charged objects is increased. what happens to the electric force between the objects?

the electric force would be decreased

what happens to the electric force between two objects if the amount of charge on one of the objects is increased?

the electric force would be increased

laws of electric charge term

the laws stating that like charges repel, opposite charges attract, and neutral objects are attracted to charged objects

what is the relationship between the number of positive and negative charges in a neutral object?

the relationship is that they are the same number

electric discharge is

the removal of electric charge from an object

vande graff generator

a device that uses friction to produce a large static charge on a metal one

electric force

a push or a pull between charged objects

electric forces

a push or pull between objects

if electrons are ______ to a neutral object, the object will become negatively charged.

added

items of insulators are

air, wood, rubber, plastic, wool, and fur

How can an object obtain an electrical charge?

an object can obtain an electrical charge by gaining electrons (to become negative) and by loosing electrons (to become positive)

the smallest particle of an element that retains the properties of that element

atom

a positive charge ____ a negative charge

attracts

a charged object __________ __ neutral charge

attracts a

the laws of electric charge are

1. like charges repel 2. opposite charges attract 3. charged objects attract some neutral ones

it takes the addition or removal of ______ electrons to produce 1c of charge

6.25 x 10^8

why do we get a shock when we rub our feet on carpet and then touch a metal doorknob?

We get a shock when we rub our feet on carpet and then touch a metal doorknob because as we scuff our feet, electrons flow from the carpet into our body. The excess electrons remain in our body until it is discharged. The shock represents the removal of electrons.

why does a balloon become charged when it is rubbed against a wool sweater?

a balloon becomes charged when it is rubbed against a wool sweater because you're creating friction between two different materials so electrons are transferred. Electrons flow from the sweater into the balloon. The sweater becomes positive while the balloon acquires a negative charge.

Static electricity refers to _______ that can be collected and held in one place

electric charges

a negatively charged particle surrounding the atom's nucleus

electron

static electricity is the temporary transfer of

electrons

examples of insulators are

glass, plastic, rubber, ceramic, dry wood, wool

items of conductors are

human body, aluminium, silver, copper and iron

a negatively charged object is brought near another object. if the two objects attract, what could the charge on the second object be?

if the negatively object us brought near another object that object must be positively charged since opposites attract

to decrease the electric force between two charged objects, the distance separating the two charges should be

increased

electric forces can increase in two ways

increasing the charge on an object and decreasing the distance

what is the difference between an insulator and a conductor

insulator is a material that does not let electrons move freely while conductors is a material that allows the electrons to move freely

how does a neutral object become negatively charged?

it becomes negatively charged when it gains electrons

how does a neutral object become positively charged?

it becomes positively charged when electrons are removed

the coloumb is the ____ of electric charge

unit

opposite charges are ____ charges

unlike

example of grounding

when a building has a lightning rod and when the lighting strikes it it goes down to the ground instead of through the building

when is an object considered to be neutral?

when it has the same number of protons and electrons

why can you charge an insulator by rubbing it, but not a conductor?

when you create friction on an insulator, electrons transfer and remain in place because insulators do not allow electrons to flow freely. When electrons enter a conductor they spread out evenly over the conductor (they do not remain fixed in one place) can return to the original object as quickly as they were transferred

example of electric discharge is

when you rub your feet on the carpet and you go to touch a doorknob the excess electrons need to be discharge so you get a shock, meaning they are being discharged