P6 molecules and matter Flashcards
Density Definition
How much mass is in a certain volume
Density Equation
Density = mass/volume
Archimedes Principle
If an object is submerged in a liquid, the level of the liquid will rise. The volume of liquid displaced will be equal to the volume of the object submerged.
1m^3
1,000,000 ml
Eureka can practical
Find mass of object
Fill eureka can with water
Place measuring cylinder under spout
Put object in water
Record volume of water in cylinder
Divide mass by volume
Purpose of eureka can practical
Find density of irregular objects
Solid to liquid
melting
Liquid to gas
Boiling
Solid to gas
Sublimation
Gas to liquid
Condensation
Liquid to solid
Freezing
Gas to solid
Deposition
Boiling
Happens at any part of the substance
Only happens above boiling point
Evaporating
Only happens at the surface
Very slow
Occurs at any temperature
Latent Heat
The energy transferred to a substance when it changes state
Does a substance change temperature during a state change?
No, the thermal energy is transferred to make or break intermolecular bonds
Internal Energy
The energy stored by the particles of a substance
Kinetic Energy
Individual motions of the particles
Relates to temperature
The more they vibrate, the more kinetic energy they have
Potential Energy
Individual positions relative to each other
It is related to the change of state
Equation of internal energy
Internal Energy = Kinetic + Potential
Specific Latent Heat
The energy transferred per kg when a substance changes state
Latent heat of fusion
melting/ freezing
Latent heat of vaporisation
boiling/ condensing
Equation for latent heat
E=mL
Energy = mass x specific latent heat
Absolute zero
when pressure = 0
approximately -273°c
where kelvin scale starts
Atmospheric pressure
100kPa
