chemistry paper 1- atoms

Question 1

RP for paper chromatography

Answer 1

draw a line at the bottom of the filter paper

using a pencil- as it is insoluble and won’t dissolve in the solvent

add a spot of ink to the line and place in beaker of water

make sure the ink doesn’t touch the water

place lid on top to prevent evaporation of water

the water will seep up carrying ink with it

each dye will move at different rates and spread out forming a spot

if these are insoluble they’ll stay on the baseline

leave to dry when the water reaches the top

the pattern = chromatography

Question 2

What is the process of filtration?

Answer 2

separates insoluble solids from liquids

filter paper is folded and the solid is left on the paper - this is the residue

Question 3

what is a way that you can separate insoluble solids from liquids?

Answer 3

filtration

Question 4

What way can you separate soluble solids from solutions?

Answer 4

evaporation + crystallisation

Question 5

What is the process of evaporation?

Answer 5

pour solution into the dish

heat the solution and the solvent will evaporate and get more

concentrated = crystals start to form

Question 6

what is the process of crystallisation?

Answer 6

pour solution into the dish and heat up

solvent will evaporate and get more concentrated

remove solution from the heat and cool

filter the crystals and leave them in a warm place to dry

(u can use a drying oven)

Question 7

simple distillation RP

Answer 7

-used to separate out a liquid from a solution with very different BP

solution is heated : the part with LBP evaporates first

vapour is then cooled, condenses and then collected

rest is left behind in the flask

simple distillation includes: water evaporates condensed and collected, ending up with salt left in flask

Question 8

what’s the problem with simple distillation?

Answer 8

you can only use it to separate things with very different boiling points

if temp goes higher than BP of the substance they will mix again, not seperate

Question 9

fractional distillation RP

Answer 9

-used to separate mixture of liquids with similar BP

put mixture in flask and put fractionating column on top + heat it

different liquid have different BP so they evaporate at different temp

lowest BP evaporates first

when the thermometer temp and liquid temp match - it reaches the top

liquid with higher BP will get part of the way up before condensing + running down to the flask

when the first liquid is collected raise temp until next one reaches the top

Question 10

John Dalton’s Theory

Answer 10

atoms were solid spheres making up different elements

Question 11

JJ Thomson’s Theory

Answer 11

Plum Pudding Model:
ball of positive charge with electron in it

Question 12

Ernest Rutherford’s Theory

Answer 12

Nuclear model:
positively charged nucleus in the centre + cloud of negative therefore there’s mostly empty space

Question 13

Neil Bohr’s Theory

Answer 13

electrons orbit and are contained in shells

Question 14

what did james chadwick discover?

Answer 14

neutrons

Question 15

what did rutherford discover?

Answer 15

protons

Question 16

what did jj thomson discover?

Answer 16

electrons

Question 17

Periodic Table before Dmitri Mendeleev?

Answer 17

-categorised by physical and chemical properties

-atomic weight

Question 18

Dmitri Mendeleev’s Periodic Table?

Answer 18

• mainly in order of atomic weight but changed it if needed

-gaps were left so elements with similar properties stayed in the same group

Question 19

Electronic structure of metals

Answer 19

don’t have many electrons to remove
are further away from the nucleus
weaker attraction
not much energy is needed to remove the electrons

Question 20

Electronic structure of non-metals

Answer 20

they have lots of electrons to to remove
stronger attraction
better to share/gain electrons
to get a full outer shell

Question 21

properties of metals

Answer 21

strong
high bpt and mpt
good at conducting heat + electricity

Question 22

properties of non-metals

Answer 22

brittle
dull
don’t conduct electricity

Question 23

Group 1 Elements

Answer 23

ALKALI
one electron in the outer shell
very reactive - soft
As you go down:
increase in reactivity as the outer electron can easily get lost as its further away so weaker attraction
low bpt and mpt
high relative atomic mass

Question 24

what happens when group 1 metal are put in water

Answer 24

react vigorously, fizzing
produce hydrogen gas : energy given out increases as u go down

Question 25

what happens when group 1 metals react with chlorine

Answer 25

react vigorously to form salts + form white salts which are metal chlorides

Question 26

Group 1 reacting with Oxygen + examples

Answer 26

make an metal oxide:
Li(2) O -lithium oxide
Na(2) O -sodium oxide
K(2) O(2) -potassium peroxide

Question 27

Group 7 Elements

Answer 27

HALOGENS
As you go down:
Less reactive as you go down as its harder to gain an extra electron as the outer shells further away from the nucleus
High bpt and mpt
high relative atomic mass

Question 28

what do more reactive halogens do to the less reactive ones?

Answer 28

displace them

Question 29

Group 0 elements

Answer 29

NOBLE GASES
boiling points increase as you go down as the electrons increase as you go down = greater intermolecular forces between them
exist as monatomic gases- single atoms not bonded