Fundamentals of Chemistry and Atomic Structure

Question 1

element

Answer 1

substance made of only one type of atom

Question 2

compound

Answer 2

2(+) atoms of different elements bonded together in a fixed ratio

Question 3

mixture

Answer 3

2(+) different elements and/ or compounds mixed together but not chemically bonded

Question 4

atom

Answer 4

smallest unit of an element that can exist

Question 5

molecule

Answer 5

2(+) atoms (of the same or different elements chemically bonded together)

Question 6

formuation

Answer 6

a mixture prepared to a formula for a specific use of application (e.g. asprin tablets, coke, petrol)

Question 7

pure

Answer 7

a substance made up of only type of atom or molecule

Question 8

states of matter

Answer 8

solid (s), liquid (l), gas (g), aqueous (aq)

Question 9

gas to liquid

Answer 9

condensation

Question 10

liquid to gas

Answer 10

vapourisation (evaporation + boiling)

Question 11

solid to liquid

Answer 11

melting

Question 12

liquid to solid

Answer 12

freezing

Question 13

solid to gas

Answer 13

sublimation

Question 14

gas to solid

Answer 14

deposition

Question 15

how do we identify what a substance is/ whether or not it’s pure?

Answer 15

by measuring and recording the temperature at which the substance melts and boils as pure substances melt and boil at specific temperatures

Question 16

how do impure substances usually melt?

Answer 16

over a range of temperatures rather than sharply at a single temperature

Question 17

why is there a flat line in the graph of heating/melting curves of a pure solution?

Answer 17

the energy is used to break/ form bonds instead of increasing/ decreasing the temperature

Question 18

all separation techniques

Answer 18

filtering, crystallisation (evaporation), distillation, chromatography

Question 19

what is filtering used for?

Answer 19

to separate insoluble solids from liquids or solutions

Question 20

what is crystallisation used for?

Answer 20

to obtain soluble solid from solution

Question 21

how is crystallisation done?

Answer 21

heated in evaporating basin until solvent boils away

Question 22

what is distillation used for?

Answer 22

to separate liquids of different boiling points where you wish to obtain the pure solvent

Question 23

how is distillation done?

Answer 23

mixture is heated until liquid with lower boiling point evaporates, then vapour is cooled until condensed in condenser then pure solvent collected

Question 24

how is chromatography done?

Answer 24

a solvent (the mobile phase) carries substances up a piece of paper (the stationary phase)

Question 25

what does the distance the substances travel depend on?

Answer 25

whether they are more strongly attracted to the water or the paper (their solubility)

Question 26

Rf

Answer 26

retention factor

Question 27

Rf equation

Answer 27

distance travelled by substance/ distance travelled by solvent

Question 28

what do you call a solution that contains the maximum possible concentration of its solute?

Answer 28

saturated solution

Question 29

diffusion

Answer 29

the movement of particles from an area of high concentration to an area of low concerntration

Question 30

factors affecting rate of diffusion

Answer 30

temperature, molecular mass, diffusion is random and other particles in the air/ water will also get in the way so it doesn’t happen instantaneously

Question 31

5 parts of the atom

Answer 31

proton, neutron, electron, shell, empty space

Question 32

atomic number

Answer 32

number of protons/ electrons

Question 33

mass number

Answer 33

number of protons + neutrons

Question 34

isotopes

Answer 34

atoms of an element with the same number of protons but different number of neutrons

Question 35

relative atomic mass

Answer 35

the average mass of all naturally occurring isotopes of an element

Question 36

calculating relative atomic mass

Answer 36

[isotope number x abundance] + [isotope number x abundance] /
100

Question 37

how many electrons can shells hold?

Answer 37

2.8.8.2

Question 38

what does the group number of the periodic table tell us?

Answer 38

the number of electrons they have in the outer shell

Question 39

what does the period number of the periodic table tell us?

Answer 39

how many occupied shells they have

Question 40

1st period

Answer 40

alkali metals

Question 41

2nd period

Answer 41

alkali earth metals

Question 42

in between 2nd and 3rd period

Answer 42

transition metals

Question 43

7th period

Answer 43

halogens

Question 44

0 period

Answer 44

noble gases