1A- Energy

Question 1

Heat energy is transferred by… (3)

Answer 1

radiation, conduction, or convection

Question 2

Conduction and convection involve the transfer of energy by..

Answer 2

particles

Question 3

dark/matt surfaces absorb infrared radiation much … than light, shiny surfaces

Answer 3

better

Question 4

solids have … forces of attraction which hold the particles close together in a … arrangement and don’t have much ..

Answer 4

strong

fixed, regular

energy

Question 5

liquids have .. forces of attraction between the particles in … arrangements

Answer 5

weaker

irregular

Question 6

gases have … forces of attraction but have … energy than liquids and solids

Answer 6

almost no

more

Question 7

conduction of heat energy is the process where…

Answer 7

vibrating particles pass on their extra kinetic energy to neighbouring particles

Question 8

insulators have … between the particles which means they conduct heat energy a lot slower

Answer 8

larger spaces

Question 9

metals conduct heat so well because the electrons are.. inside the metal

Answer 9

free to move

Question 10

convection occurs when..

Answer 10

the more energetic particles move from the hotter region to the cooler region and take their heat energy with them

Question 11

when a gas cools, the particles in the gas .. and lose …

Answer 11

slow down

kinetic energy

Question 12

the rate of evaporation will be faster if...
t
a
d
s

Answer 12

temperature is higher (average particle energy is higher, so more particles have enough energy to escape)

airflow over the liquid is greater (a greater airflow means air above the liquid is replaced quicker so the evaporated substance can transfer quicker)

density is lower (forces between particles are weaker, so more particles have enough energy o overcome the forces and escape the liquid)

surface area is larger (more particles near surface to escape)

Question 13

the rate of condensation will be faster if..

t
a
d
s

Answer 13

temperature of the gas is lower (particle energy is lower so they can slow down enough to come together and form liquid droplets)

airflow is less (concentration of the substance in the air is higher so condensation rate can be greater)

density is higher (forces between particles are stronger so fewer have enough energy to break away from the forces and instead clump together to form liquid)

temparature of surface area the gas touches is lower

Question 14

how can you limit and reduce energy transfers in product?

Answer 14

• double walled with a vacuum (stops air conduction and convection)
• silvered walls (keep heat loss by radiation to a minimum)
• insulating foam (minimises heat conduction)
• stopper made from plastic + filled with cork/ foam (reduces heat conduction through it)

Question 15

animals in warm climates have … ears than those in cold climates to help control heat transfer + why?

Answer 15

larger ears with a large surface area- allows them to lose heat by radiation

Question 16

why do animals in cold climates have smaller ears?

Answer 16

because the smaller surface area can minimise heat loss by radiation and it conserves body heat