Unit 2 Flashcards
How is pressure inside containers created
gas particles collide with the walls
how does increasing temperature affect pressure inside containers
increases the velocity of particles which increases pressure
what happens to the pressure when volume of a container is decreased
the number of collisions increase so pressure increases
what happens to particles at absolute zero
they have no kinetic energy
this is found at -273 celsius or 0 kelvin
what is brownian motion
the random collisions between microscopic particles in a suspensions and the particles of gases or liquids
what happens when a material is heated
it expands
what happens when a solid is heated
the particles will vibrate more and push each other further apart
what happens to the temperature when a substance changes state
there is no change to temperature
what is the boiling and melting point of water
boiling is 100 C
melting is 0 C
what happens during evaporation
particles escape from a liquid surface causing it too cool
why is the expansion of different states different
gases expand the most
liquids expand more than solids
solids expand the least because their bonds are strongest
what is the specific heat capacity
the energy required to change the temperature of 1 kg of a substance by 1 C
the higher the heat capacity, the more energy it takes to raise the temperature
specific heat capacity formula
C = change in energy
—————————
mass X change in temperature
what happens when liquids are heated
the fastest particles escape first, the average energy of the remaining particles decrease which causes a decrease in temperature
what is the difference between evaporation and boiling
evaporation only happens at the surface and at any temperature
boiling happens throughout the liquid at the boiling point
how does surface area affect evaporation
rate of evaporation increases as surface area increases
how is energy transferred
thermal conduction through materials
how do convection currents transfer energy within a fluid
due to density changes
hot materials expand and rise then cool and contract
what are convection processes responsible for
air currents
what happens when object absorb and emit infrared radiation
causes them to warm or cool
how does infrared radiation get transferred
doesnt require a medium
what factors affect the amount of radiation emitted or absorbed
surface color( dark surfaces emit and absorb better than light surfaces)
surface texture( matt and rough surfaces are better than smooth and shiny)
why are nonmetals bad conductors
conduction is slow since energy is passed through vibration
metals conduct much faster since they have free electrons
why are gases poor conductors
particles are too far apart to pass energy
are liquids good conductors
they are fairly poor since their particles are less tightly packed
when objects emit more radiation than they absorb, waht are they doing
cooling down
objects that absorb more radiation they they emit,what are they doing
warming up
what does rate of emisson depend on
temperature- the higher the temperature difference, the more radiation will be emitted
surface area- the larger the area the more energy can be absorbed or emitted
what is the formula for latent heat
amount of heat absorbed or released per unit mass
what is latent heat
energy released or absorbed during a change in state
