P3 PARTICLE MODEL OF MATTER

Question 1

state the different states of matter in order of density of atoms?

Answer 1

least dense = gas
= liquid
=solid

Question 2

describe the particle arrangement of a solid?

Answer 2

tightly packed in a regular arrangement. particles can only vibrate on the spot

Question 3

describe the particle arrangement of a liquid?

Answer 3

close together , but with irregular arrangement . they can flow over each other

Question 4

describe the particles arrangement of a gas?

Answer 4

separated , with no regular arrangement , particles can move freely

Question 5

what is always conserved when a substance undergoes a change of state

Answer 5

mass

Question 6

how can a change of state differ from chemical change?

Answer 6

the material can return to having its previous properties if the change is reversed.

Question 7

sublimation?

Answer 7

when a solid changes into a gas without passing through the liquid stage

Question 8

evaporation?

Answer 8

liquid changes into gas

Question 9

condensation?

Answer 9

gas changes into liquid

Question 10

when water boils in an open pan why does the mass of the pan of water appear to decrease?

Answer 10

some of the water will evaporate and turn into water vapour . this will leave the pan meaning the mass of the pan will decrease, the mass of the whole system however remains constant

Question 11

explain the processes involved when a bathroom mirrors mists up?

Answer 11

hot water evaporates to form water vapour
this water vapour lands on the cooler mirror
the vapour condenses and returns to liquid on the mirrors surface

Question 12

what is the internal energy of a substance?

Answer 12

energy stored by the particles.

sum of the total kinetic potential energies that make up the system

Question 13

how does heating affect the energy of a substance?

Answer 13

heating transfers energy to the substance.

increases the energy of the particles that make up the substance

Question 14

what 2 things can heating a substance do?

Answer 14

raise temperature

change the state of the substance

Question 15

what 3 factors determine the temperature change of a system?

Answer 15

mass of substance being heated.

type of material

energy inputted into the system

Question 16

specific heat capacity?

Answer 16

the amount of energy needed to increase its temperature of 1kg of a substance by 1°C

Question 17

describe how the internal energy and temperature of a substance changes when a change of state occurs?

Answer 17

internal energy of a substance will be increased or decreased.
temperature of the substance will remain constant.

Question 18

specific latent heat?

Answer 18

the amount of energy needed to change 1kg of a substance with no change in temperature

Question 19

specific latent heat fusion?

Answer 19

the energy required to change 1kg of a substance from soild state to liquid state without a change in temperature

Question 20

specific latent heat of vaporisation?

Answer 20

the energy required to change 1kg of a substance from liquid state to gas state without a change in temperature

Question 21

describe the motion of gas?

Answer 21

constant random motion

Question 22

what factors affect the average kinetic energy of gas molecules?

Answer 22

temperature of the substance.
The higher the temperature , the higher the average kinetic energy of the molecules.

Question 23

what effect does increasing temperature have on the pressure of the gas when held at constant volume?

Answer 23

pressure of the gas increases as the temperature increases.

Question 24

why does pressure increase as temperature increases?

Answer 24

The kinetic energy of molecules increases.
collisions between molecules becomes more frequent .
greater rate of change of momentum
greater force and therefore pressure.

Question 25

if gas a is at low pressure , and gas b is at high pressure what can be said about the rate of collisions in each gas?

Answer 25

there are more collisions per sec in gas b than in gas a.
the rate of collisions is higher in b

Question 26

describe the force that the pressure of a gas exerts on the walls of its container?

Answer 26

net force acts at right-angles to the containers surface.

force increases = pressure increases

Question 27

explain how increasing the volume of a gas results in a decrease of pressure?

Answer 27

molecules become more spread out and so time between collisions increases.
this reduces the rate of collisions.
rate of change of momentum decreases, and so force exterted on a container decreases, resulting in a lower pressure.

Question 28

what can be said about the product of pressure and volume for a fixed gas at a constant temperature

Answer 28

it is constant

Question 29

unit used for pressure?

Answer 29

pascal (pa)

Question 30

what increases when you do work on a gas?

Answer 30

the internal energy of a gas.

can also lead to an increase in temperature

Question 31

why does the temperature of air inside a bike pump increase when it is pumped?

Answer 31

work is done on a gas when its compressed.

doing work on a gas increases its internal energy, so also increases the average kinetic energy of the molecules.

temperature increases with an increase of average kinetic energy