Science 9 Chapter 7 Final Exam Review Preparation

Front 1

What is acetate?

Back 1

a type of plastic used in photographic film and overhead transparencies

Front 2

What is an action-at-a-distance force?

Back 2

forces that can have an effect on an object without touching it

Front 3

What is an atom?

Back 3

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

Front 4

What is charging by conduction?

Back 4

process of transferring charge between objects by touching or rubbing

Front 5

What is charging by induction?

Back 5

process of rearranging electrons on a neutral object by bringing a charged object close to it

Front 6

What are conductors?

Back 6

materials that allow electrons to move freely on and through them

Front 7

What are contact forces?

Back 7

forces that have an effect only on objects that they can touch

Front 8

What is a coulomb?

Back 8

the unit of electric charge, named after the French physicist Charles Coulomb; one coulomb is the amount of charge passing a point in one second when one ampere of current is flowing

Front 9

What is electric force?

Back 9

a push or pull between charged objects

Front 10

What are electrons?

Back 10

negatively charged particles surrounding the atomic nucleus

Front 11

What is a force?

Back 11

a push or a pull exerted on an object

Front 12

What is grounding?

Back 12

connecting a conductor so that electric charge flows into Earth's surface

Front 13

What are insulators?

Back 13

materials that do not allow electrons to move easily on or through them

Front 14

What are the laws of static charge?

Back 14

physical laws that state that like charges repel, opposite charges attract, and neutral objects and charged objects attract each other

Front 15

What is neutral?

Back 15

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

Front 16

What is the nucleus?

Back 16

(in chemistry), the positively charged centre of an atom, which contains protons and neutrons

Front 17

What is a proton?

Back 17

positively charged particle in the atomic nucleus

Front 18

What is static charge?

Back 18

an electric charge that can be collected and held very neatly fixed in one place

Front 19

What is the Van de Graaff generator?

Back 19

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

Front 20

How does an electroscope work?

Back 20

1) an object with a suspected static charge is brought toward the knob
2) electrical charge move to the metal and down to the foils
3) since each leaf has the same charge they repel each other and separate

Front 21

What is friction?

Back 21

-objects rub against each other
-can result in 1 object losing an electron and another gaining electrons

Front 22

Give examples of insulators

Back 22

rubber, plastic, dry wood, glass etc.

Front 23

What are free electrons?

Back 23

the electrons in metals that are free to move throughout the conductor

Front 24

1 C (One Coulomb) of charge is equal to...

Back 24

6.25 times 10 ^ 18 electrons

Front 25

What is lightning?

Back 25

the result of a build-up of static charge in clouds due to friction created as hot air rises rapidly and rubs ice crystals and dust particles in cloud banks

Front 26

What are applications of static electricity?

Back 26

-allows plastic wrap to cling
-decrease air pollution
-paint used on cars

Front 27

What are at a distant forces (examples)?

Back 27

gravity, magnetic, electric

Front 28

What is the property of static charge?

Back 28

-charge is never created nor destroyed
-the process of charging is really moving the charge from one place to another (negative only)

Front 29

Explain charging by induction using an electroscope

Back 29

-rod with negative charge brought close to electroscope
-electrons move down leaves
-leaves separate
-remove rod and leaves fall

Front 30

Explain charging by conduction using an electroscope

Back 30

-rod with negative charge touches knob
-transfer of electrons from rod to electroscope
-leaves separate
-remove rod
-leaves are still separated

Front 31

What is charging by conduction with a positively charged object?

Back 31

-electrons from electroscope would be attracted to positive object
-metal leaves would become positively charged after electrons have been transferred to the (positive) object

Front 32

What is static discharge?

Back 32

-static charge with eventually wear off
-electrons may slowly move into moisture in the air, OR discharge quickly in a spark