PARTICLE MODEL OF MATTER Flashcards
describe the particle structure in a solid
strong forces of attraction between particles which hold them in a fixed position, closely together to form a regular lattice structure.
Because the particles are fixed solids have a solid definite shape and volume. The particles vibrate in a fixed position
what happens when a solid is heated
The particles gain more kinetic energy and vibrate, even more, weakening the force between the particles, at the melting point, the particles have enough energy to break free from the bonds, so the solid melts into a liquid.
describe the particle structure of a liquid
weaker forces of attraction between the particles, so the particles move around at random directions at low speed, forming an irregular arrangement. The particles are closer together so they have a definite volume but they do take up the shape of the container
what happens when a liquid is heated
The particles gain more kinetic energy, weakening the forces between the particles when you reach the boiling point, the particles have enough energy to break the bonds so the liquid turns into a gas
what happens when a liquid is cooled
when you cool down a liquid, the particles won’t have enough energy to overcome the attraction between the particles, forming new bonds, freezing the liquid into a solid
describe the particle structure in a gas
no forces of attraction, particles have more energy so they are free to move at random directions at a high speed. They do not have a definite shape or volume, they take up the shape of the container because the particles are spread out.
what happens when a gas is heated
They gain more kinetic energy and expand the container or increase the pressure
what happens when a gas is cooled
When we cool gas, the particles won’t have enough energy to overcome the forces between the particles, so they will create new bonds, condensing the gas into a liquid
is a state of change a chemical change or physical change
physical change because you dont end up with new substances
is mass conserved in a closed system?
mass is conserved in a close system
what is density
density is the mass of a substance per unit of its volume
the formula for density, mass and volume
density = mass/ volume
1 g/cm^3 into kg/m^3
1 g/cm^3 = 1000kg/m^3
required practical = measuring the density of a regular solid
1) measure the mass of the solid using a balance and record it
2) measure its width, length and height using a ruler and calculate the volume using the correct formula for the shape
3) substitute the values you got for the mass and volume into the formula density=mass/volume, and calculate the density
required practical = measuring the density of an irregular solid
1) measure the mass of the solid using a balance and record it
2) Fill a eureka can with water up to the outlet, and place a measuring cylinder next to the outlet
3) submerge the irregular object into the eureka can, the water displaced from 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 irregular object.
5) substitute the values you got for the mass and volume into the formula density=mass/volume, and calculate the density
required practical = measuring the density of a liquid
1) place an empty beaker on the balance and zero the balance
2) pour 10cm^3 of water into the beaker
3)measure the mass of the water by reading off the balance
4) substitute the values you got for the mass and volume into the formula density=mass/volume, and calculate the density
larger volume = more accuracy because it minimises the effects of uncertainty