11. P6 Molecules and Matter

Question 1

Explain why object such as ice and wood float when placed in water.

Answer 1

Ice and wood are less dense than water.

Question 2

What is the definition of the “density” of an object?

Answer 2

It is the mass per unit volume of an object.

Question 3

The state of matter where the particles are linked by strong forces. They are packed closely together and move very little. The particles usually form a regular and specific pattern.

Answer 3

Solid

Question 4

The state of matter where the particles have weaker bonds. They are still tightly packed but may move around each other.

Answer 4

Liquid

Question 5

The state of matter where particles are far apart and are in constant random motion. There is no interactive between the particles.

Answer 5

Gas

Question 6

The temperature at which a solid turns into a liquid .

Answer 6

Melting Point

Question 7

The temperature at which a liquid turns into a gas.

Answer 7

Boiling Point

Question 8

Nome of process when a solid changes to a liquid.

Answer 8

Melting

Question 9

Name of process when a liquid changes a gas at the boiling point

Answer 9

Boiling

Question 10

Name of process when a liquid changes to a gas below the boiling point.

Answer 10

Evaporating

Question 11

Name of process when a gas changes to a liquid.

Answer 11

Condensing

Question 12

The name given to the sum of the energy of the particles of a substance due to their individual motions and positions.

Answer 12

Internal Energy

Question 13

Property of a substance which is the amount of energy required to raise the temperature of one kilogram of a substance by one degree Celsius.

Answer 13

Specific Heat Capacity

Question 14

Often represented by the symbol ‘c’.

Answer 14

Specific Heat Capacity

Question 15

Units of specific heat capacity.

Answer 15

J/kg°C.

Question 16

The amount of energy required to change the state of one kilogram of the substance with no change in temperature.

Answer 16

Specific Latent Heat

Question 17

Often represented by ‘L’.

Answer 17

Specific Latent Heat

Question 18

Units of specific latent heat.

Answer 18

J/kgC

Question 19

When molecules collide with the wall of their container they exert a force on the wall. The total force exerted by all of the molecules inside the container on a unit of area of the wall is called?

Answer 19

Gas pressure

Question 20

What is the amount of space that a substance or object occupies?

Answer 20

Volume

Question 21

What is the unit of volume?

Answer 21

Metres cubed (m³)

Question 22

What is the mass per unit volume of a material?

Answer 22

Density

Question 23

What is the standard unit of density?

Answer 23

kg/m³

Question 24

When a solid changes into a gas when it is heated without becoming a liquid first.

Answer 24

Sublimation

Question 25

The amount of energy required to change one kilogram of a solid into a liquid with no change of temperature.

Answer 25

Specific Latent Heat Of Fusion

Question 26

The amount of energy required to change one kilogram of a liquid into a gas (vapour) with no change of temperature.

Answer 26

Specific Latent Heat Of Vaporisation

Question 27

What is meant by the random motion of a gas molecule?

Answer 27

Particles moving with a range of different speeds in random directions.

Question 28

What observations made which provided evidence for the random motion of a gas molecule?

Answer 28

Brownian motion of smoke particles.

Question 29

Explain how the haphazard and unpredictable motion of smoke particles under a microscope were explained?

Answer 29

Air molecules moving randomly collided with the smoke particles. Providing them with random forces, causing the unpredictable motion.

Question 30

The unit of pressure.

Answer 30

Pascals (Pa)

Question 31

Equation linking energy transferred and the specific heat capacity?

Answer 31

E = m x c x ?

Question 32

Equation linking energy transferred and the specific latent heat?

Answer 32

E = m x L

Question 33

Equation linking density, volume and mass of an object?

Answer 33

density = mass/volume

Question 34

What happens to the pressure of a gas in a sealed container when the temperature is increased?

Answer 34

Pressure increases with the temperature of a sealed container of gas.

Question 35

Explain why the temperature of a sealed container of gas affects the pressure of the gas.

Answer 35

As the temperature increases, the speed increases. Therefore the molecule collide with a greater force and more of them collide with the surface per second.

Question 36

How do you calculate the volume of a cuboid?

Answer 36

..

Question 37

How do you calculate the volume of a sphere?

Answer 37

..

Question 38

What state has particles which are least energetic?

Answer 38

Solid

Question 39

What state has particles which are most energetic?

Answer 39

Gas

Question 40

Describe the two difference between boiling and evaporation of a liquid?

Answer 40

Boiling occurs at the liquids boiling point, evaporation at a temperature below this point. Boiling occurs from throughout a liquid, evaporation occurs at the surface.