P3 - Particle Model Of Matter Flashcards
What does the state of a material depend upon?
It depends on the strength of the forces of attraction between the particles of the material,
Which is determined by the:
• structure of the substance and type of bonds holding the particles together
• temperature
• pressure
Describe the structure and properties of solids
Solids have strong forces of attraction between particles holding them close together in fixed positions, therefore:
- Solids have a definite shape and volume
- The particles form a regular lattice arrangement
- The particles vibrate in their positions
Describe the structure and properties of liquids
Particles in liquids have weak forces of attraction. They are randomly arranged and free to move but tend to stick close together.
- Liquids have a definite volume but don’t have a definite shape
- The particles move constantly with random motion
Liquids expand slightly when heated.
Describe the structure and properties of gases
Particles in gases have very weak forces of attraction, so are far apart. They’re free to move and travel in straight lines
- Gases don’t have a definite shape or volume
- The particles move constantly with random motion
Gases expand slightly when heated, or their pressure increases.
How do colliding gas particles create pressure?
Particles in gases are free to move around
When they move they collide with each other and the sides of the container and exert a force on it
Pressure = force exerted per unit area
So in a sealed container, the outward gas pressure is the total force exerted by all of the particles in the gas on a unit area of the container walls
How does increasing the temperature of a gas increase pressure?
When temperature is increased, energy is transferred into the kinetic energy stores of its particles
Higher temperature = higher average energy
As the energy of a gas increases, the average speed of its particles increases
So for a gas at constant volume, increasing temp increases pressure
What is density?
What is the equation for density?
Mass = how much matter an object has
Volume = how much space something takes up
Density (Kg/m^3) = mass (kg) / volume (m^3)
P = m / v
How do you measure the density of a solid object?
How do you measure the density of a liquid?
What is internal energy?
Why is change of state a physical change (rather than a chemical change)?
It is the same substance you started with, just in a different form.
There are no new substances created.
(Changing state requires energy)
What is sublimation?
The physical change of a substance from a solid directly to a gas, without passing through a liquid state.
What are the changes of state?
Liquid to solid = freezing or solidifying
Solid to liquid = melting
Liquid to gas = boiling or evaporating
Gas to liquid = condensing
Solid to gas = sublimating
What is specific latent heat?
What is the equation for specific latent heat?
The amount of energy needed to change the state of 1kg of a substance without changing its temperature.
E = mL
Energy (J) = mass (kg) x specific latent heat (j/kg)
