1.1 particulate nature of matter

Question 1

matter can exist in diff states depending on

Answer 1

temp and pressure

Question 2

diff physical states of matter are characterised by(2):

Answer 2

• different arrangement
• and movement of particles
  this is dependednt on amount of KE a particle possesses

Question 3

properties of solid and its consequences (4）

Answer 3

properties
1. particles are close together
2. particles have lower energy than in the other two states.
3. particles can only rotate and vibrate about fixed positions
4. strong forces of attraction between particles

consequences:
1. definite shape
2. definite volume
3. incompressible
4. high density

Question 4

properties of liquid and its consequences (4)

Answer 4

• particles are slightly further apart than in solids
• particles have larger amounts of energy than those in solid state
• particles an move about quite freely around one another while in close proximity
• moderate forces of attraction between particles

consequence
- indefinite shape
- definite volume
- negligible compressibility
- moderate to high density

Question 5

properties of gases and its consequences(4)

Answer 5

properties:
- particles are far apart from one another
- particles have much more energy than the two other states
- particles can move rapidly, haphazardly into any space available
- very little forces of attraction between particles

consequences:
- indefinite shape
- indefinite volume (affected by temp and pressure)
- highly compressible
- low density

Question 6

changes of state (7 kinds+desc+energy absorbed or released?)

Answer 6

sublimation, s->g, absorbed
deposition g->s, released
evaporation l->g, absorbed
boiling l->g, absorbed
condensation g->l, released
freezing, l->s, released
melting s->l, absorbed

Question 7

heating and cooling curves(axis+desc shape+explain)

Answer 7

x-time
y-temp
1. upward sloping regions: temp increasing as substance heated->KE increase + particles vibrate faster
2. plateau: temp stays constant as energy input is being used to overcome intermolecular forces that exist between the particles = temp no increase
3. upwards again
solid -melting-> liquid -evaporation->gas

Question 8

density def + eqn

Answer 8

density of a substance is its mass per unit volume
d=m/v

derived:
m=do

Question 9

kinetic energy:

Answer 9

Kinetic energy is a form of energy that an object or a particle has by reason of its motion

Question 10

element

Answer 10

is made up of the same kind of atom and cannot bc brokwn down into a simpler substance

Question 11

compounds

Answer 11

are made up of two or more different elements that are chemically combined

Question 12

molecule

Answer 12

a molecule contains two or more atoms that are chemically bonded together. the atoms can be the same or different

molecules are electrically neutral -> do not have +ve/-ve charge

Question 13

two kinds of mixtures

Answer 13

heterogenous
homogenous

Question 14

mixture

Answer 14

two or more substances that are not chemically combined, meaning each substance retains its original properties.

Question 15

homogenous mixtures

Answer 15

same composition throughout

gaseous, liquid, or solid mixture that has the same proportions of its components throughout a given sample

e.g. seawater, solutions

Question 16

fractional distillation

Answer 16

a technique that is used to separate the components of a mixture based on their different boiling points

Question 17

heterogenous mixture

Answer 17

has a non-uniform composition -> will separate into layers on standing -> immiscible

Question 18

immiscible

Answer 18

not capable of combining to form a homogenous mixture when mixed

Question 19

stoichiometry coefficient

Answer 19

numbers in front of each formula in a balanced eqn -> tell us the molar ratios of reactants and products in a balanced eqn