Particle model/Forces and matter Flashcards
Describe the particle arrangement in a solid
Particles are in a regular arrangement, touching, and vibrate but cannot move.
Describe the forces of attraction between particles in a solid
Forces of attraction are strong and hold particles closely together.
Describe the particle arrangement in a liquid
Particles are close/touching but can move past one another and are in an irregular pattern.
Describe the forces of attraction between particles in a liquid
The forces of attraction are not strong enough to hold them in fixed positions, but keep them close together.
Describe the particle arrangement in a gas.
Particles are far apart and moving quickly, in a random way.
Describe the forces of attraction between particles in a gas.
Forces of attraction between particles in a gas are weak.
Which state(s) of matter is/are compressible?
Gasses
Which state(s) of matter can flow?
Liquids and Gasses
What is sublimation?
When a solid turns straight into a gas without becoming a liquid first
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.
Physical
What relationship can you use to calculate the density of a substance?
Density = mass/volume
ρ (kg/m3) = m(kg)/V(m3)
Which quantity is represented by the greek letter rho (ρ)?
Density
List the pieces of equipment needed to find the density of an irregular object that sinks.
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
Define specific heat capacity
The amount of energy needed to increase the temperature of 1kg of a substance by 1 °C.
The amount of thermal energy stored in something depends on which 3 things?
its temperature
its mass
the material it is made from
Temperature is a measure of…
the movement of particles
Define specific latent heat
The amount of energy required to make 1kg of a substance change state
For a given substance, which would be greater - the specific latent heat of melting or the specific latent heat of evaporation?
Evaporation
What happens to the temperature when an object changes state?
It stays the same
What equation relates change in thermal energy, mass, specific heat capacity and temperature difference?
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)
What equation is needed to calculate the energy needed to change the state of an amount of a substance.
Q = m x L
Q = energy (J)
m = mass (kg)
L = specific latent heat (J/kg)
What causes a pressure in a gas?
The forces on the walls of a container caused by the moving particles hitting the walls
Why does increasing the temperature of a fixed volume of gas increase its pressure? (Give two reasons)
Faster particles = greater force per collision
More collisions = greater total force
What is absolute zero (in words)?
The temperature at which particles stop moving and have zero kinetic energy
What is absolute zero in °C?
0k = -273°C
To convert from °C into kelvin, what do you need to do?
add 273
What is the difference between elastic and inelastic distortion?
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.
Describe the relationship between force and extension for a spring stretched a small amount (in words).
Force is directly proportional to extension.
Describe the relationship between force and extension for a rubber band (in words).
As force increases extension increases, but it is non-linear.
What does the spring constant of a spring represent?
The stiffness of the spring
What equation links Force and extension for a spring?
F = k x
where
F = Force (N)
k = spring constant (N/m)
x = extension (m)
What is the equation to calculate work done in stretching a spring?
E = 1/2 k x2
E = Energy transferred in stretching (J)
k = spring constant (N/m)
x2 = extension squared (m2)
How can you find the spring constant from a force extension graph?
Find the gradient - check what way round your axes are! Gradient = k if x is on the x axis
