P3-particle Model Of Matter Flashcards
(19 cards)
What is density?
The mass per unit volume in a substance.
Equation for density
Density (kg/metre cubed). =.mass (kg) (g)
(g/cm cubed). Volume (m)(cm)3
In terms of particles talk abt a dense and less dense material
In a dense material particles of packed tightly together in a list of materials, they are more spread out. If you compress, the material of the particle would move closer together, and it would become more dense .not changing mass but decreasing its volume.
Talk about the arrangement of solids
Strong forces of attraction hold the particles close together in a fixed regular arrangement. The particles don’t have much energy so they can vibrate about that fixed position is the density is generally highest in the state of the particles are closest together.
Talk about arrangements in liquids
There are weaker forces of attraction between the particles particles are close together we can move past each other and form in regular arrangements to have more energy than the particles in a solid. The move in random direction to low speeds liquids are generally less dense than solids.
Talk about the arrangement in gases
There is almost no forces of attraction between the particles particles have more energy than liquids and solids are free to move and travel in random directions at high speeds gases are generally less dense than liquids. They have low densities
Practical-density of a solid object
1) use the balance to measures mass
2) if it’s a regular solid start by measuring its length, width and height with an appropriate piece of equipment, e.g. ruler, then calculate it volume using the relevant formula for that shape
3) for an irregular solid, you can find it the volume by submerging in a Eureka Can filledwith water. The water displaced by object will be transferred to the measuring cylinder.
4) record the volume of water in the measuring cylinder. This is the volume of the object.
5) use the objects mass and volume in the formula to find its density
Practical-density of a liquid
1)Place measuring cylinder on the balance and zero, the balance
2) pour 10 mL of the water into the measuring cylinder and record the liquid mass
3) pour another 10 mL into the measuring cylinder, repeating the process until the cylinder useful and recording the total volume and mass each time
4) for each measurement, use the formula to find the density (1ml=1cm cubed)
5) take an average of you calculate the density is. This is the density of the liquid.
What is internal energy?
Internal energy is the energy stored by the particles, making up a system
The energy stored in a system installed by the particles. The internal energy of the system is the total energy that particles have in the kinetic and potential energy stores.
Heating increases internal energy
Change in temp or change in state
Change in temp-the size of the chain depend on the mass of the substance shc and energy input
Change in state-occurs if substance is heated enough enough energy to break the bonds
What is the different chnages of state
S-L=melting
L-S=freezing
L-G= boiling or evaporating
G-L=condensing
S-G=sublimating
G-S=deposition
What happened to the mass in a change of state and is it physical or chemical?
Physical because you don’t end up with a new substance. Same substance in different form can be reversed number of particles on change mass is conserved.
What’s happening when a substance is melting and boiling
You’re still putting an energy and so increasing internal energy energy is being used to break bonds between particles rather than raising the temperature there a flat sports on the heating Graph where energy being transferred by heating but not being used to change temp
What’s happening when is often have been condensed a froze
Bonds are forming between particles which releases energy. This means the internal energy decreases with the temperature doesn’t go down until all the substance has turned into liquid or solid
What is specific latent heat?
Amount of energy needed to change 1 kg of it from one state to another without changing its temperature
What is the difference between specific latent heat of fusion in specific latent heat of vaporisation?
The specific latent heat for changing between a solid, and a liquid is called a specific latent heat of fusion
The specific latent heat between in between a liquid and gas is called the specific latent heat of vaporisation
Relationship between average, energy and kinetic stores and temperature
If you increase temperature of a guess, you transfer energy into the kinetic energy stores
The higher the temperature, the higher, the average energy
So increasing the temperature of a gas , average speed of its particle increases
Relationship between collide and gas particles and pressure
When the particles collide with something, they exert a force on it in a sealed container that out with gas pressure is the total force exerted by all of the particles in a gas
Faster particles have more frequent collisions increase in gas pressure. Increasing temperature will increase the speed and so increase pressure. (If volume is kept constant)
If temperature is constant increasing volume of gas mains particles are more spread out and collide less often gas pressure decreases
Pressure and volume inversely proportional
Relationship between change in pressure and change in volume
Pressure of a gas causes, a random outwards force at right angles
There is also a force on the outside of the container due to pressure of the gas around it
If a container easily changes, it says there any changes in these pressures will cause the container to compress or expand due to the overall force
Doing work on a gas can increase its temperature
Doing, work on a gas increases its internal energy which can increase its temperature
You can do work mechanically-bike pump.
