Science, Physics - Electricity & Energy (Heat)

Question 1

static electricity

Answer 1

• because of the build-up of electric charge
• called ‘static’ energy because the charge is unable to flow

Question 2

how does static electricity happen

Answer 2

• 2 insulating materials are rubbed together => friction between materials cause charge to be transferred from 1 materials to the other
• one material has more electrons (negative charge)
• the other has less electrons (positive charge)

Question 3

negative or positive charge?

Answer 3

it depends on the object that gains or loses

Question 4

circuit

Answer 4

• path of electricity
• used everyday

Question 5

3 basic components of a circuit

Answer 5

• energy source: battery
• conductor: wires
• electrical load: bulb/buzzer
• switch (optional)

Question 6

types of circuits

Answer 6

1. simple circuit
2. parallel circuit
3. series circuit

Question 7

simple circuit

Answer 7

• 3 basic components
  -> energy source
  -> conductor
  -> electrical load

Question 8

parallel circuit

Answer 8

• 2 paths

Question 9

series circuit

Answer 9

• multiple electrical loads
• only one path

Question 10

current

Answer 10

• the measure of flow of charges (electrons) thru wires and components in one sec
• electrons will only flow out through the negative pole of battery
• measured in amps/ampere
• ammeter is the one used to measure
  -> must be connected to the current to measure
• written in A

Question 11

voltmeter measures ____
ammeter measures _____

Answer 11

voltage
current

Question 12

voltage

Answer 12

• potential difference (another word)
• a “pressure” that pushes electricity
• measured in volts (V)

Question 13

voltage or current ? (in circuits)

Answer 13

• series = voltage is shared
• parallel = currents are shared

Question 14

model (in circuits)

Answer 14

• scientists often use models to help them explain difficult concepts

Question 15

heat

Answer 15

• measured in Joules (J)
• temperature is HOW you measure heat

Question 16

3 ways to transfer heat

Answer 16

1. conduction (all 3 matters)
2. convection (only fluids)
3. radiation (waves)

Question 17

conduction

Answer 17

heat makes the particles move faster => particles will vibrate and transfer the heat between each other

• one side that heats up will transfer the heat to the other side

Question 18

rate of heating particles (conduction)

Answer 18

1. solids (close together, transfer easy)
2. liquids (gaps in between particles, transfer is slower)
3. gas (big gaps in between particles)

Question 19

evaporation

Answer 19

• takes thermal energy away from the surface
• process of liquid changing to gas
• when particles evaporate from the surface of a liquid, the remaining liquid is cooler because it has less thermal energy (evaporation cooling)

Question 20

factors that affect the rate of evaporation

Answer 20

• temperature
• air movement
• surface area
• humidity
• density

Question 21

convection

Answer 21

• only can happen if particles can flow
• always related to density

Question 22

less dense =
more dense =

Answer 22

1. rise
2. sink

Question 23

thermal expansion

Answer 23

• particles expand because heat increases their energy (vibrates more)
• number of particles are the same, just expanded

*hot water rises

Question 24

radiation

Answer 24

• doesn’t require a medium (state of matters)
• can occur in a vacuum
• infra-red radiation can travel through vacuum