Science 9 - Chapter 7 Test

Question 0

electrons

Answer 0

negative charge

Question 1

how is static charge produced?

Answer 1

electron transfer

Question 2

protons

Answer 2

positive charge

Question 3

when is an atom neutral

Answer 3

equal number electrons & protons

Question 4

insulator

Answer 4

electric charges don’t move easily

Question 5

conductor

Answer 5

electric charges can move more freely

Question 6

unit of measuring charge

Answer 6

coulomb

Question 7

static charge/electricity

Answer 7

charges collected & held in one place

Question 8

static

Answer 8

stationary or not moving

Question 9

atom structure

Answer 9

centre: nucleus –> neutrons & protons (positive)
first electron/valence ring/shell –> 2 electrons
second electron/valence ring/shell –> 4 electrons

Question 10

movement in atom

Answer 10

• positive nucleus vibrates but remains in position

- only electrons move in solid material (all solid material charged by transfer of electrons)

Question 11

electron removed

Answer 11

negative charge taken away

Question 12

electron added

Answer 12

negative charge increases

Question 13

when does friction occur?

Answer 13

when objects rub against each other

Question 14

what does friction result in?

Answer 14

one object losing electrons while other gains electrons. electrons added to neutral objects through friction stay in one place. electrons removed from one location on insulator NOT replaced, only insulators can retain static charge.

Question 15

free electrons

Answer 15

free to move throughout the conductor

Question 16

Van de Graff generator

Answer 16

uses friction to produce static charge on metal dome, moving belt produces static charge at base of generator. Belt carries charge to top (where it collects on the dome.)

Question 17

grounding

Answer 17

allowing charges to flow into earth’s surface

Question 18

lightning is caused by…?

Answer 18

buildup of static electricity

Question 19

attraction rules

Answer 19

• opposite charges attract
• like charges repel
• neutral charges attract both negative and positive charges
• two neutrals have no affect

Question 20

contact forces

Answer 20

only effect objects that they touch

Question 21

electric force

Answer 21

push/pull between charged objects

example of action-at-a-distance force

Question 22

action-at-a-distance forces

Answer 22

apply force without touching

Question 23

increasing charge results in

Answer 23

increased electric force

Question 24

decreased amount of charge results in…?

Answer 24

decreased electric force

Question 25

decreased distance between charged objects results in…?

Answer 25

increase of electric force

Question 26

charging by conduction

Answer 26

charging neutral object by touching charged object, extra electrons spread evenly over entire surface of neutral object.

(no electrons transferred from object, instead, repositions electrons inside of object)

Question 27

why does a charged balloon stick to the wall?

Answer 27

because a positive charge is induced on the surface of the wall

Question 28

true or false; most metals are good conductors

Answer 28

true