particle model of matter

Question 1

what is density?

Answer 1

the amount of mass in a given volume of space

Question 2

what is mass?

Answer 2

how much matter an object has, measured in kg and uses and electrical balance

Question 3

what is volume?

Answer 3

how much space something takes up, measure in cm³ or m³, length x width x height

Question 4

what is the equation that links density mass and volume?

Answer 4

density= mass/ volume

Question 5

how are particles arranged in solids?

Answer 5

• incompressible/ have a fixed volume
• do not flow
• hard to change the shape of
• denser than gas and liquids

Question 6

how are the particles in a liquid arranged?

Answer 6

• hard to change volume because particles are close
• they flow
• easy to change the shape of
• more dense than gas but less that solids

Question 7

haw are the particles in a gas arranged?

Answer 7

• compressible
• they flow
• easy to change the shape of
• less dense than a solid and liquid

Question 8

changes of state?

Answer 8

melting: solid to liquid
freezing: liquid to solid
boiling: liquid to gas at boiling point
evaporating; liquid to gas when the temperature of the liquid is lower than boiling point
condensing: gas to liquid
sublimating: solid to gas without going through the liquid state

Question 9

what is internal energy?

Answer 9

the energy that the particles have.
it is the total of:
- the kinetic energy particles have due to their individual motion relative to each other
- the potential energy they have due to their individual positions relative to each other
* it does not include gravitational potential energy or the kinetic energy of the substance *

Question 10

what is the specific heat capacity?

Answer 10

this is the amount of energy needed to raise the temperature of 1kg of a material by 1°C

Question 11

what is the specific heat capacity equation?

Answer 11

energy= mass x specific heat capacity x change in temperature

Question 12

what is latent heat energy?

Answer 12

the amount of energy needed to cause 1kg of a material to change state

Question 13

what is the latent heat energy equation?

Answer 13

energy= mass x latent heat

Question 14

latent heat observation?

Answer 14

• as we heat a solid, its temperature will increase
• when it begins to melt, its temperature will stay the same until all of it has melted
• it is now a liquid, and the temperature will rise again
• until it begins to boil then it will stay at the same temperature until all of it has vapourised.

Question 15

latent heat explanation?

Answer 15

• this is because the heat energy transferred to the substance while it is changing state is called latent heat
• latent heat does not make the substance hotter instead it is used to break the bonds between the particles so they can change state

Question 16

explain gas pressure

Answer 16

• as the particles collide with the sides of the container , they exert a force on it
• this is what gas pressure is; the force exerted by the gas particles as they collide on the sides of the container
• increasing the temperature therefore increases the pressure