chapter 5 section 2

Question 1

conduction def

Answer 1

transfer of thermal energy by collisions between particles in matter

Question 2

why does conduction occur?

Answer 2

because particles in matter are in constant motion

Question 3

think about the spoon example with conduction…

Answer 3

• as one end of the spoon heats up, the kinetic energy of the particles that make up that part of the spoon increases
• these particles collide with neighboring particles
• conduction transfers thermal energy to the other end of the spoon as particles with more kinetic energy transfer

Question 4

T? or F?: Conduction transfers thermal energy while it transfers matter.

Answer 4

F: …thermal energy without transferring matter

Question 5

how is thermal energy transferred?

Answer 5

by the collisions between particles, NOT by the movement of matter

Question 6

T? or F?: Conduction spreads thermal energy from cooler to warmer areas.

Answer 6

F: …warmer to cooler areas.

Question 7

what does the rate at which thermal energy is transferred depend on?

Answer 7

the material

Question 8

thermal energy transfers by conduction fastest through what forms of matter?

Answer 8

solids and liquids

rather than gases

Question 9

why does thermal energy transfer faster by conduction through solids and liquids?

Answer 9

particles that make up gases are further apart, so collisions between particles occur less frequently than they so for solids of liquids

Question 10

best conductors for thermal energy are…

Answer 10

metals

Question 11

why are the best thermal energy conductors metals?

Answer 11

there are electron that are not bound to individual atoms but can move easily throughout metals, because of this, collisions between these electrons and other particles in the metal enable thermal energy to be transferred more quickly than in other materials

Question 12

convection def

Answer 12

the transfer of thermal energy through a fluid by the movement of warmer and cooler fluid from place to place

Question 13

why are gases considered liquids?

Answer 13

both gases and liquids can ‘flow’ so they are both classified as fluids

Question 14

what happens to particles when convection occurs?

Answer 14

more energetic particles move from one place to another, unlike the collisions of particles in conduction

Question 15

T? or F?: more energetic particles means that they have higher speed.

Answer 15

T

Question 16

T? or F?: as particles move faster, the tend to move closer together.

Answer 16

F: … tend to move farther apart; as a result the fluid expands as its temperature increases

Question 17

expansion def

Answer 17

increased volume

Question 18

remember, density

Answer 18

mass/volume (m/v)

Question 19

so, as volume increases…

Answer 19

density decreases; the same is true for parts of fluid that have been heated

Question 20

the density of warmer fluid is …

Answer 20

less than that of the surrounding cooler fluid

Question 21

the warmer proportions of a fluid rise to the…

Answer 21

top of the fluid and the cooler portions sink to the bottom

Question 22

is a fluid is heated from below…

Answer 22

convection currents form