p3 Flashcards
what are solids?
what are liquids?
what are gasses?
-Solids- horces of attraction which hold the particles together in a fixed regular arrangement.The particles don’t have much energy so they can only vibrate about their fixed positions
Liquids-they are a weaker force of attraction.The particles are close together and can move past each other and form irregular arrangements they have more energy than the particles in a solid they move in random directions at low speeds
Gases- there are almost no forces attraction between the particles.More energy than in liquids and solids they are free to move and are constantly moving in random direction’s and speeds
how are particles in gasses?
what happens when they collide with something ?
what is pressure?
eg?
-particles in gasses are free to move around as they move they bang into each other and whatever else happens to get in the way
-When they collide with something they exert a force on it
-Pressure is the force exerted per unit area
EG in a sealed container the outward gas pressure is total force exerted by all the particles in the gas on a unit area of the container walls.
what happens when you increase the temperature of a gas?
what is the temperature of a gas related to?
the higher the temp ? the higher …….?
-you transfer energy into kinetic energy store
-The temperature of a gas is related to average energy in the kinetic energy store of the particles in a gas.
-the higher the average energy
what happens when the particles are travelling quicker?
what does each particle having a larger momentum do?
-It means they hit the side of the container more often in a given amount of time
-they exert a larger force when they collide with the container
increasing pressure
what is density?
what is the formula?
Density of a material tells us the mass for a given volume.
Density=mass/Volume
p=density -Kg/m^3
m-mass kg
volume-m^3
what is the practical steps for solid object? density(5)
1.First use a balance to measure its mass
2.If its a regular solid start by measuring its length,width and height with an appropiate piece of equipment.Then caculate it’s volume using the relevant formula for that shape.
3.For an irregular solid you can find it’s volume by submerging it in a eureka can filled with water.The water is displaced by the object will be transferred to the measuring cylinder.
4.Record the volume of the water in the measuring cylinder.This is the volume of the object.
5.Plug the object’s mass and volume in the formula of the density
what is the practical for the density of a liquid? (5)
1.Place the measuring cylinder on the balance and 0 the balance
2.Pour 10ml of the liquid into the measuring cylinder and record the liquid’s mass
3.Pour another 10ml into the measuring cylinder repeating the process until the cylinder is full and recording the total volume and mass each time.
4.For each measurement use the formula to find the density.
5.Finally take an average of your caculated densities.This will give you the value for the density of the liquid.
what is the internal energy?
-The energy stored in a system by particles.It is the total kinectic energy and potential energy of all particles (atoms and molecules)that make up a system
solid to liquid =Melting
Liquid to solid=Freezing
Solid to gas=Sublimating
Liquid to gas=boiling
Gas to liquid=Condensing
what happens when change of state takes place?
what type of change are they?
-When they take place mass is always conserved.We are not adding or taking away any particles.
-They are physical changes.If we reverse the changes the material covers it original properties.
what is specific latent heat ?
what is the equation?
-Specific latent heat of a substance is the amount of energy required to change the state of 1 kilogram of the substance with no change in temperature.
E=M X L
e-energy joules
m-mass kg
L-SLH j/kg
what happens when a substance is melting or boiling?
-Your still putting the energy and increasing the internal energy but the energy is used for breaking bonds between particles rather raising the temperature.The flat spots on the heating graph where energy is being transferred by heating but not being used to change the temperature.
What happens when a substance is condensing or freezing?
bonds are forming between particles which releases energy.This means internal energy decreases but the temperature doesn’t go down until all the substance has turned to liquid or a solid.The flat part of this graph shows this energy transfer
what is specific latent heat of fusion?
what is specific latent heat of vaporisation?
-The energy required to change 1kg of a substance from a solid to a liquid with no change in temperature
-The energy required to change 1kg of a substance from a liquid to a vapor with no change in temperature
