the periodic table

Question 1

what is the periodic table?

Answer 1

its a list of elements arranged in order of increasing proton numbers

Question 2

what is a group?

Answer 2

its a vertical coloumn of elements
there are 8grps, I-VII n O
it runs frm top to bottom

Question 3

what is a period?

Answer 3

its a horizontal coloumn of elements
there are 7 periods
runs frm left to right

Question 4

Periodic trends:

metallic n non-metallic properties across the period

Answer 4

from left to right across a period, thr is a decrease in metallic properties n an increase in non-metallic properties:
from very metallic to metalloids(Silicon) to non-metallic
better RAs to better OAs
from basic to amphoteric to acidic

Question 5

metallic properties down a grp

Answer 5

thr is an increase in metallic properties

Question 6

non-metallic properties down a grp

Answer 6

thr is a decrease in non-metallic properties

Question 7

why is the metallic properties down a grp as such?

Answer 7

going down a grp, the size of the atoms increases so atomic radius increases so the -vely charged valence e of an element will b further away frm the +vely charged nucleus so an element down a grp will thus lose its valence e more easily so its more reactive

Question 8

electronic structure:

we can obtain the elctronic config frm

Answer 8

the element’s proton no.-> deduce period n grp no.

Question 9

the no. of eshells is the same as

Answer 9

the period no. of the element

Question 10

the no. of valence e is the same as

Answer 10

the grp no. of the elements

Question 11

elements w the same no.of valence e hv

Answer 11

similar chemical n physical properties tht r determined by no. of valence e

Question 12

group 1 elements: Alkali Metals

Answer 12

all the elements hv similar properties since thy belong in the same grp

Question 13

the physical properties of alkali metals

Answer 13

they are soft n can b cut thru easily
low mp n bp which decreases down the grp
low densities which increases down the grp
thy r vry shny metals but whn thy r cut since thy r so reactive thyll oxidise n bcome black

Question 14

chemical properties of alkali metals

Answer 14

• they are highly reactive metals so they have to be stored in oil to prevent it frm reacting w air n water
• thy can just lose 1 valence e to attain noble gas electronic structure
• reactivity increases down the grp bcos down the grp, atomic radius increases so it is easier to lose the valence e since the electrostatic forces of e btwn the +vely charged nucleus n negatively-charged valence e gets weaker so its easier to lose e

Question 15

reaction tht alkali metals can take part in

Answer 15

1. they can react w cold water to form alkali + hydrogen

they r all exothermic!!

Question 16

are alkali metals powerful oa or ra?

Answer 16

powerful ra!! since all alkali metals form ions w a charge of +1 by losing 1e frm the outer shell which thy can lose easily/readily
reducing power increases down the grp as the metals has a higher tendency to lose e down the grp( n bcome oxidised)

Question 17

alkali metals form what kind of cmpnds?

Answer 17

form ionic cmpnds n their cmpnds hv similar chemical formulas n r soluble in water

Question 18

whn placed in a fire, Li glows:

Answer 18

bright red

Question 19

whn placed in a fire, Na bcomes:

Answer 19

bright yellow

Question 20

whn placed in a fire, K produces a:

Answer 20

violet colour

Question 21

whn placed in a fire, rubidium is:

Answer 21

dark red

Question 22

whn placed in a fire, caesium is:

Answer 22

light blue

Question 23

Group 7 elements: Halogens;

physical properties of halogens

Answer 23

halogens r non-metals tht exist as diatomic covalent molecules w SMS(weak wander Waals FOA)
it has low mp bp which increases down the grp
it is coloured and the colour bcome darker/colour intensity increases down the grp
density increases down the grp

Question 24

why does halogens have an increasing mp n bp down the grp?

Answer 24

down the grp the molecular masses/sizes of halogens increase so the vdwfoa btwn molecules increases so a highr amt of heat energy is req to overcome the foa so mp/bp increases

Question 25

r halogens soluble in water?

Answer 25

all halogens r soluble in water no matter what state it is in

Question 26

colour of F2(g)-> gas at rm temp!!

Answer 26

pale yellow

Question 27

colour of F2(aq)

Answer 27

colourless

Question 28

colour of Cl2(g)-> gas at rm temp!!

Answer 28

yellowish-green

Question 29

colour of Cl2(aq)

Answer 29

colourless

Question 30

colour of Br2(l)

Answer 30

reddish-brown

Question 31

colour of Br2(aq) n Br2(g)

Answer 31

brown/ orangey brown

Question 32

colour of I2(g)

Answer 32

violet

Question 33

colour of I2(s)

Answer 33

black

Question 34

colour of I2(aq)

Answer 34

reddish brown not yellowish-brown!

Question 35

astantine

Answer 35

black solid

Question 36

chemical properties of halogens:

Answer 36

1. they are reactive non metals since thy hv 7 valence e n only require 1 e to achieve stable octet noble gas config

Question 37

halogens react w metals to form?

Answer 37

salts-> called halides

Question 38

reactivity of halogens increases or decreases down the grp? n why?

Answer 38

decreases down the grp bcos the atomic radius of the halogens increases down the group, so the esfoa between the +vely charged nucleus and -vely charged electron gets weaker right, so its harder to attract an electron down the grip, which is why reactivity decreases down the grp

Question 39

r halogens powerful oa or ra? does their oxidising/reducing power increase or decrease down thr grp?

Answer 39

powerful oa’s! oxidising power also decreases down thr grp since OA is directly related to reactivity

Question 40

halogen displacement rctns

Answer 40

a more reactive halogen will displace a less reactive halogen frm its halide sln
RMBR DO NOT SPLIT THE AQ STATES IN THE IONIC EQNS!!!!!
more reactive halogen + halide of less reactive halogen(the colour is decided by cation tho) -> salt + halogen(less-reactive one)

Question 41

transition metals properties(4)

Answer 41

1. high mp bp
2. high densities
3. variable oxidation states
4. form coloured cmpnds: colour of hydrated compnd may b diff frm tht of the anyhydrous cmpnd-> helps us test for presence of H2O

Question 42

uses of transition metals(2)

Answer 42

1. used in dyes n paints to produce diff colours

2. used as catalysts-> increases SOR n remains chemically unchanged at the end of rctn

Question 43

group VIII/0 elements-> Noble gases aka

Answer 43

inert gases or rare gases

Question 44

properties of noble gases(7)

Answer 44

1. non-metals
2. monoatomic
3. coloured gases at rm temp
4. low mp n bp which increases down the grp
5. insoluble in water
6. do not form compounds
7. bcos thy r UNREACTIVE-> dont lose, gain or share e bcos thy hv stable duplet(He) or octet electronic config