Summary AQA A Level Chemistry 3.2.1 Periodicity

-periodic recurring regularly :




3 2 1 . .
.

Periodicity
.
1 Classification




?
.
2 Physical properties of Period 3 elements


-




Perios
- e -


-


-




m




1S




"
25 2p
35 3p 3d
4 s 4p4d4f

The periodic table elements according proton number
.
arranges to
·




·
All elements along a
period have the same number of electron shells
. All elements

down a
group
:
same no .

of outer electrons
.



Elements are classified
S-block groups 142 d-block transition metals
: :




into blocks that show
3 to 0 f-block :
radioactive elements
p-block groups
:




configuration
:
electron




Macromolecular
(giant covalent) atomic




-
giant metallic


metals
↑ semical
molscar ·
non-metals noble

group D
gas




-
S block P block
noble gas
havegiant P4
- One r
"C
C2




- unreactive
Na
Mg Al si p s Ar
metals , so : lose
electrons to


! --
form ionic
-- ↓
compounds has some
metallic
2
form ionic compounds or share
foure's in outer
properties either accept es to

shell : forms 4
their outer shell es to form covalent compounds.
covalent bonds


-
ATOMIC RADIUS


Along a period :
atomic radius decreases
. The increased nuclear charge (for
the same no of shells) increases the attraction from the nucleus and pulls
the outer shell electrons closer to the nucleus
.


NISATION
ENERGY

Along a
period
:
isnisation energy increases
. As the atomic radius decreases
and nuclear charge increases ,
the attraction between the nucleus outer
shell electrons increases and :· the electrons are held more strongly
. This
means that more energy is required to remove the outer electron & ionise
the atom
.