thermal effects

Question 1

solids

Answer 1

have fixed shape and volume
geld close together by attraction forces (bonds)
they vibrate but cannot change positions

Question 2

liquids

Answer 2

they have fixed volume but can flow to the up the shape of the container
the vibrate but they can change positions

Question 3

gases

Answer 3

no fixed volume or shape
they take up the shape of the container quickly
free of any attractions
move at high speeds

Question 4

energy of particles

Answer 4

all particles have internal energy

Question 5

internal energy (thermal energy)

Answer 5

kinetic energy + potential energy

Question 6

temperature

Answer 6

same temperature same amount of kinetic energy per particle

Question 7

absolute zero (0K)

Answer 7

-273 °C

Question 8

Expansion

Answer 8

the slight increase in volume when heating up a material due to the speeding up of particles that vibrate to take up more space

Question 9

contraction

Answer 9

the decrease in volume due to cold temperatures

Question 10

affect of temperature on pressure

Answer 10

as temperature increases pressure increases
but they do not increase proportionally (graph doesnt start from origin)

Question 11

affect of temperature on volume

Answer 11

as temperature increases volume increases

Question 12

conduction

Answer 12

thermal energy transfers from the hot end to the cold end of a conducting material

Question 13

conductors

Answer 13

material is full of free moving electrons conducting heat and electricity
ex: metals, graphite

Question 14

insulators

Answer 14

material has no free moving electrons blocking current and heat
ex: wood , plastic

Question 15

how does conduction happen

Answer 15

when an object is heated free moving electrons speed up as the randomly move through the object making atoms move faster transferring thermal energy through the whole object

Question 16

convection

Answer 16

a circulating stream

Question 17

convection current cycle

Answer 17

1. heater warms water causing it to rise as it become less dense
2. warm water cools down
3. cold water sinks as it becomes denser
4. cold water returns to heater

Question 18

where is convection used at home

Answer 18

1. hot water system
2. room heating
3. refrigerator

Question 19

radiation

Answer 19

light heats up materials and colours that absorb it

Question 20

colours

Answer 20

darker colours absorb heat
bright colours reflect heat
black emits energy at a faster rate than white

Question 21

evaporation

Answer 21

a liquid below boiling point changes into a gas (water vapour)
faster particles near the surface escape as gas because they have enough energy

Question 22

boiling

Answer 22

vapour bubbles rise and expand as they burst to release water vapour

Question 23

condensation

Answer 23

when a gas changes into a liquid

Question 24

change of state

Answer 24

solid to liquid&raquo_space; melting
liquid to gas&raquo_space; evaporation
gas to liquid&raquo_space; condensation
liquid to solid&raquo_space; solidification

Question 25

specific heat capacity

Answer 25

energy transferred = mass * specific heat capacity change in temperature
e= mcΔt powertime = mcΔt

Question 26

latent heat

Answer 26

energy absorbed in order to change state
energy transferred = mass * specific LATENT heat
e= mL