6.3 Temperature and Heat

Question 1

Kinetic molecular theory of matter

Answer 1

states that matter is made up of particles
(molecules, atoms, ions) that are in constant
random motion

these particles are continually vibrating, rotating, and colliding with one another.

Question 2

The particles that make up matter have ________ because of their constant motion.

Answer 2

kinetic energy

Question 3

As particles _______, their energy constantly
alternates between kinetic energy and elastic
potential energy.

Answer 3

vibrate

Question 4

Particles also have __________ energy due to the forces of attraction or chemical bonds between them.

Answer 4

potential

Question 5

Thermal energy

Answer 5

the total kinetic and potential energy of the particles within an object

Question 6

Thermal energy is internal energy –
the energy associated with the _______ of the particles.

Answer 6

movement

Question 7

An object has _____ energy in addition to any potential energy or kinetic energy it may have as a
whole.

Answer 7

thermal

Question 8

A car moving over a bridge has kinetic energy because

Answer 8

it is moving

Question 9

A car moving over a bridge has gravitational potential energy because

Answer 9

it is high on the bridge

Question 10

A car moving over a bridge has thermal energy because

Answer 10

of the particles that make up the car.

Question 11

As particles move, they collide, and when they
do, they transfer ____________ back and forth
among themselves.

In this way, energy can be ________ from one part of an object to another, or even from one object to another object.

Answer 11

kinetic energy; transferred

Question 12

The temperature of a substance is the average
_____________ of the particles.

Answer 12

kinetic energy

Question 13

The greater the average kinetic energy of the particles, the _______ the object’s temperature.

Answer 13

higher

Question 14

Temperature is measured in either Celsius or
Kelvin. The standard SI unit is the ______.

0° C = 273 K

Answer 14

Kelvin

Question 15

Absolute zero

Answer 15

-lowest temperature that is theoretically possible
-occurs at a temperature of 0 Kelvin, or -273°C.

Question 16

At absolute zero, molecular motion and energy would be _______.

Answer 16

minimal

Question 17

_______ is the energy transferred from a warmer
object to a cooler one.

Answer 17

Heat

Question 18

Heat is always transferred from a _____ object
to a ________ object.

Answer 18

hotter; colder

Question 19

If two objects are the same temperature, there will be __________.

Answer 19

no heat transfer

Question 20

However, when two contacting surfaces are
rubbed against one another, _______ exists as
the particles in the substance to move past
each other and their kinetic energy gets
transferred into _______ energy, causing a ____
in temperature.

Answer 20

friction; thermal; rise

Question 21

Conduction

Answer 21

The transfer of thermal energy through direct
contact of substances.

Example: hot chocolate in a mug

Question 22

Convection

Answer 22

The transfer of thermal energy through the
bulk movement of particles from one
location to another. This occurs in liquids and
gases. Convection is a natural stirring of a
fluid: hotter, less dense material flows up
while cooler, denser material flows down.
Eventually all the material is heated to a
uniform temperature.

Example: boiling water, air in a room.

Question 23

Radiation

Answer 23

Radiation is the transfer of thermal energy
through fast moving particles or
electromagnetic waves.

Example: heat given off by the sun

Question 24

Heat capacity (c)

Answer 24

the amount of thermal energy needed to change the temperature of an object or system by 1
Kelvin, or 1°C.

Question 25

The amount of thermal energy (Q) you need to
heat an object depends on three things:

Answer 25

The mass of the object

How much temperature change you are
trying to get

The type of material (specific heat capacity)

Question 26

Q =

Answer 26

thermal energy

Question 27

m =

Answer 27

mass

Question 28

c =

Answer 28

specific heat capacity

Question 29

ΔT =

Answer 29

temperature change

Question 30

the principle of heat exchange

Answer 30

When two substances at different
temperatures are mixed, the amount of
thermal energy lost by the hotter substance in
cooling is equal to the amount of thermal
energy gained by the colder substance in
warming.

Question 31

The thermal energy gained by the cooler
substance ______ the thermal energy _____ by
the warmer substance.

Answer 31

equals; lost