Physics - Matter Flashcards
what is kinetic theory
explains that in a substance at different states, particles are exactly the same but have different amounts of kinetic energy and are arranged differently
what happens to kinetic energy when a substance is heated
increases
what do changes of state require in terms of bonds
energy to weaken or break bonds
what does it mean when gradient on kinetic energy/time graph is 0
energy is being transferred to break bonds
differences between pure and impure substances boiling/melting points
pure will change state at one temperature specifically whereas impure have a range of melting/boiling temperatures and cannot be said to have a specific melting/boiling point
solid state
amount of energy?
force of attraction?
movement of particles?
density of particles?
amount of energy = least
force of attraction = strong
movement of particles = only vibrate, fixed positions, close together
density of particles = very dense, lack of movement
liquid state
amount of energy?
force of attraction?
movement of particles?
density of particles?
amount of energy = more than solid
force of attraction = weaker than solid
movement of particles = can move slightly, not fixed, further apart than solids
density of particles = less dense than solid
gas state
amount of energy?
force of attraction?
movement of particles?
density of particles?
amount of energy = most
force of attraction = very weak
movement of particles = many directions, fast, far apart
density of particles = least dense
example of macroscopic motions
solid cannot flow
liquid/gas can flow
what happens to temperature when thermal energy is transferred to a body
temperature rises unless state change
what happens to temperature when thermal energy is removed from a body
temperature decreases
why doesnt the temperature change during state changes
because the energy is changing the separation between particles
latent heat of vaporisation
liquid to gas
boiling
condensing
latent heat of fusion
solid to liquid
melting
freezing
equation for amount of energy required to change state of substance
energy (J) = mass (kg) x latent heat (J/kg)
when can you model a gas as an ideal gas
when you assume that particles obey Newton’s laws and that the volume of gas particles is negligible compared to overall gas volume (both at room temperature)
what does a gas particle consist of
rapid random motion and not exerting forces on one another
particles of gas colliding with each other
each collision exerts tiny force
these add up to an average force per unit area , or pressure, exerted by gas
gas particles in a container
collide with walls of container
equates to a certain force per unit volume also known as the pressure of gas
pressure volume constant
pressure x volume = constant
pressure temperature constant
pressure / temperature = constant
pressure and volume relationship
directly proportional
pressure and temperature relationship
inversely proportional
pressure volume constant constant equation
(P x V) / T
density equation and units
density (kg/m^3) =
mass (kg) x volume (m^3)
samples composed of the same substance will have … densities
the same
despite their volume and mass being different
how to measure volume of regular object
ruler
how to measure volume of an irregular object
volume of water it displaces
pressure equation
pressure (Pa) =
force (N) / area (m^2)
what is 1 Pa (pascals) equal to
1 N/m^2
hydrostatic pressure equation
depth (m) x fluid density (kg/m^3) x gravitational field strength (N/kg)
