CHAPTER 3 : PERIODICITY
Features of the periodic table
-
arranged in order of increasing atomic number
-
sub-levels :
s,p, dif
-
I group : the alkali metals ; group 17
:
halogens
d-block : transition metals
group 18 : noble gases ;
La-Lu Lanthanoids
:
: Ac-Ir : actinoids B
,Si, Ge :
metalloids
Topic : Oxidation state & oxidation number
*
Copper (I) oxide Fet +ci
I
oxidation number Fells -
Fron (III) dichloride usageof Roman number oxidation state
Oxidation state is the charge of an ion in a
compound if all bonds in the compound would be
ionic
The rules for oxidation states
-
pure element have o s .
" O
group 1 +1
:
-
+2
-
group 2 :
-
fluorine 1 : -
-
hydrogen :
compound with group ord -1
except :
-
oxygen : -2
except percovides HcO
↳
-
o S
. .
of metals valency coxidation number)
=
↳
always positive
, Topic :
Physical properties
Size of an atom 1Number of electron shells
-
Li size of atom increases , because each
Ne successive molecule of group has more
electron shells
C .
Charge of a nucleus if number of shells is the
same
Na iMg igAl Si
14 15
P
> decrease
Going from left to the right the size of atoms
decreases bc of increasing nuclear charge ,
hence produ
cing stronger attraction
The atomic radius is the distance from the nucleus to the
outermost electron
The ionic radius
Cations Anions
Na Nat Cl C-
160 102 100 181
[Nej3s' [Ne] [Ne) 35sp5 (Ne] 35 3 ps
II protons 17 protons
II e- 10e 17e- 18 e
Electronegativity -
the ability of an atom to attract
electrons in a covalent bond
Electron affinity -
the energy change when an electron
Is added to an isolated atom in a gaseous state
Features of the periodic table
-
arranged in order of increasing atomic number
-
sub-levels :
s,p, dif
-
I group : the alkali metals ; group 17
:
halogens
d-block : transition metals
group 18 : noble gases ;
La-Lu Lanthanoids
:
: Ac-Ir : actinoids B
,Si, Ge :
metalloids
Topic : Oxidation state & oxidation number
*
Copper (I) oxide Fet +ci
I
oxidation number Fells -
Fron (III) dichloride usageof Roman number oxidation state
Oxidation state is the charge of an ion in a
compound if all bonds in the compound would be
ionic
The rules for oxidation states
-
pure element have o s .
" O
group 1 +1
:
-
+2
-
group 2 :
-
fluorine 1 : -
-
hydrogen :
compound with group ord -1
except :
-
oxygen : -2
except percovides HcO
↳
-
o S
. .
of metals valency coxidation number)
=
↳
always positive
, Topic :
Physical properties
Size of an atom 1Number of electron shells
-
Li size of atom increases , because each
Ne successive molecule of group has more
electron shells
C .
Charge of a nucleus if number of shells is the
same
Na iMg igAl Si
14 15
P
> decrease
Going from left to the right the size of atoms
decreases bc of increasing nuclear charge ,
hence produ
cing stronger attraction
The atomic radius is the distance from the nucleus to the
outermost electron
The ionic radius
Cations Anions
Na Nat Cl C-
160 102 100 181
[Nej3s' [Ne] [Ne) 35sp5 (Ne] 35 3 ps
II protons 17 protons
II e- 10e 17e- 18 e
Electronegativity -
the ability of an atom to attract
electrons in a covalent bond
Electron affinity -
the energy change when an electron
Is added to an isolated atom in a gaseous state
