CH 18: Electric Charge

Question 1

what are the two charges

Answer 1

positive and negative charge

Question 2

what charges repel and which attract

Answer 2

like charges repel
opp. charges attract

Question 3

what unit is for charges

Answer 3

coulomb
elementary charge: e = 1.6x10^-19 C
1 C = 6.25 x 10^18

Question 4

what are the three common types of electrical materials

Answer 4

conductors
insulators
semi conductors

Question 5

what use is a conductor

Answer 5

electrons in conductors can freely move around because they are not tightly bound to a specific atom (metals)

Question 6

what use is an insulator

Answer 6

electrons in insulators can tightly bound and cannot freely move much (glass, plastic, wood, etc)
can have excess charges (dont have to be neutrally charged)

Question 7

what use is a semi conductor

Answer 7

electrons are tightly bound until a small charge is applied, then they start to conduct (silicon)

Question 8

whats a current

Answer 8

moving electrons
in conductors, charges can evenly distribute themselves unless an external charge is applied (then they respond to those)

Question 9

what is coulombs law

Answer 9

the magnitude of the electrostatic force between two charges
𝐹 = 𝑘 |𝑞1𝑞2|/𝑟2
k is the constant