Physics Flashcards
What are the different properties of solids, liquids and gases?
Is this a waste of time?
yes.
What is density?
What is diffusion?
e.g perfume spreading through air
Does gas have mass?
Gas has mass and therefore weighs!
This shows you that when evaporation happens, mass is conserved but the particles go into the air, you just cannot see them!
What is air pressure?
Air pressure is caused by the force of air gas particles bumping into things.
Air is forced into a balloon under pressure. As the number of air particles and collisions increase, the pressure inside the balloon increases.
Why is air used inside car tyres
Air is a gas
Gases can flow
Easier to fill up tyre with air
Gases fill the space of the container
Air will inflate the tyre
Gases can be compressed
Air can act as suspension to absorb shock on road
Why is water used in radiators?
Water is a liquid
Liquids can flow
Water can be easily pumped through radiators
Liquids keep their volume
Water will only expand a little when heated which keeps the pressure low enough to be safe.
Liquids have high density
Lots of water particles can carry lots of heat energy
Why is steel used for railway lines?
Steel is a solid
Solids keep their shape
Steel can be used to build a fixed structure
Solids cannot be easily compressed
Steel tracks will not be deformed by heavy trains running on them
Solids have a high density
Steel is a strong material that will last long
What happens to particles as they get heated?
Materials can change their state because energy is ADDED or REMOVED from its thermal store.
As a liquid is heated, its particles gain MORE kinetic energy.
The particles vibrate faster and move further apart.
The liquid expands.
The particles don’t expand.
Their size and mass stays the same.
What is sublimation?
When substances have their melting and boiling point close together, they can go from solid straight to gas. This is sublimation
What is the melting point?
The melting point is the temperature at which a substance changes from a …….solid….. to a ……liquid……
What is the boiling point?
The boiling point is the temperature at which a substance changes from a ………… to a ………….
You have to tell me the state of matter at 20 0C , 150 0C and -50 0C.
What is the difference between thermal energy and temperature?
Thermal energy is the total energy of particles moving in a substance, and temperature is a measure of how fast the particles are moving on average.
Thermal is the energy that you add, temperature is a measure of that energy
D,D
C
Explain the definition of a melting point and boiling point with particles
Tell me about conduction in a solid
Explain this heating curve
If a solid is heated, its temperature rises (particles are speeding up) until it reaches the melting point of the solid.
At the melting point, the temperature stops rising whilst the solid melts. This is because energy is going into separating the particles rather than speeding them up.
Once all the solid has melted, the temperature starts to rise again (particles continue to speed up) until it reaches the boiling point.
At the boiling point the temperature again stays the same as energy goes into further separating the particles.
Why do materials expand when heated and contract when cooled?
Answers should refer to:
How much energy the particles have.
How much the particles are vibrating.
What happens to the space between the particles.
What happens to the volume/size of the object.
Remember: Particles do not change shape or size!!
Many substances expand when heated because when heated, the particles (atoms or molecules) in a substance gain energy (in the form of heat) and vibrate more.
This means the space between the particles increases. So the volume of the substance increases
