Particle model/Forces and matter

Question 1

Describe the particle arrangement in a solid

Answer 1

Particles are in a regular arrangement, touching, and vibrate but cannot move.

Question 2

Describe the forces of attraction between particles in a solid

Answer 2

Forces of attraction are strong and hold particles closely together.

Question 3

Describe the particle arrangement in a liquid

Answer 3

Particles are close/touching but can move past one another and are in an irregular pattern.

Question 4

Describe the forces of attraction between particles in a liquid

Answer 4

The forces of attraction are not strong enough to hold them in fixed positions, but keep them close together.

Question 5

Describe the particle arrangement in a gas.

Answer 5

Particles are far apart and moving quickly, in a random way.

Question 6

Describe the forces of attraction between particles in a gas.

Answer 6

Forces of attraction between particles in a gas are weak.

Question 7

Which state(s) of matter is/are compressible?

Answer 7

Gasses

Question 8

Which state(s) of matter can flow?

Answer 8

Liquids and Gasses

Question 9

What is sublimation?

Answer 9

When a solid turns straight into a gas without becoming a liquid first

Question 10

During a change of state mass is conserved and the substance recovers its original properties if the change is reversed. We say it is a ___________ change.

Answer 10

Physical

Question 11

What relationship can you use to calculate the density of a substance?

Answer 11

Density = mass/volume

ρ (kg/m3) = m(kg)/V(m3)

Question 12

Which quantity is represented by the greek letter rho (ρ)?

Answer 12

Density

Question 13

List the pieces of equipment needed to find the density of an irregular object that sinks.

Answer 13

Mass balance to measure mass (before it gets wet!)
Eureka can/displacement can to submerge the object
Measuring cylinder to measure the volume of displaced water

Question 14

Define specific heat capacity

Answer 14

The amount of energy needed to increase the temperature of 1kg of a substance by 1 °C.

Question 15

The amount of thermal energy stored in something depends on which 3 things?

Answer 15

its temperature
its mass
the material it is made from

Question 16

Temperature is a measure of…

Answer 16

the movement of particles

Question 17

Define specific latent heat

Answer 17

The amount of energy required to make 1kg of a substance change state

Question 18

For a given substance, which would be greater - the specific latent heat of melting or the specific latent heat of evaporation?

Answer 18

Evaporation

Question 19

What happens to the temperature when an object changes state?

Answer 19

It stays the same

Question 20

What equation relates change in thermal energy, mass, specific heat capacity and temperature difference?

Answer 20

ΔQ = m x c x Δθ

Q = energy (J)
m = mass (kg)
c = specific heat capacity (J/kg°C)
θ = temperature (°C)
Δ = ‘change in’ (Greek letter Delta)

Question 21

What equation is needed to calculate the energy needed to change the state of an amount of a substance.

Answer 21

Q = m x L

Q = energy (J)
m = mass (kg)
L = specific latent heat (J/kg)

Question 22

What causes a pressure in a gas?

Answer 22

The forces on the walls of a container caused by the moving particles hitting the walls

Question 23

Why does increasing the temperature of a fixed volume of gas increase its pressure? (Give two reasons)

Answer 23

Faster particles = greater force per collision

More collisions = greater total force

Question 24

What is absolute zero (in words)?

Answer 24

The temperature at which particles stop moving and have zero kinetic energy

Question 25

What is absolute zero in °C?

Answer 25

0k = -273°C

Question 26

To convert from °C into kelvin, what do you need to do?

Answer 26

add 273

Question 27

What is the difference between elastic and inelastic distortion?

Answer 27

The object returns to its original shape and size once the force is removed if it has deformed elastically. After inelastic distortion it will not return to its original shape/size once the force is removed - it is permanently deformed.

Question 28

Describe the relationship between force and extension for a spring stretched a small amount (in words).

Answer 28

Force is directly proportional to extension.

Question 29

Describe the relationship between force and extension for a rubber band (in words).

Answer 29

As force increases extension increases, but it is non-linear.

Question 30

What does the spring constant of a spring represent?

Answer 30

The stiffness of the spring

Question 31

What equation links Force and extension for a spring?

Answer 31

F = k x

where

F = Force (N)
k = spring constant (N/m)
x = extension (m)

Question 32

What is the equation to calculate work done in stretching a spring?

Answer 32

E = 1/2 k x2

E = Energy transferred in stretching (J)
k = spring constant (N/m)
x2 = extension squared (m2)

Question 33

How can you find the spring constant from a force extension graph?

Answer 33

Find the gradient - check what way round your axes are! Gradient = k if x is on the x axis