2. PERIODICITY PROPETIES OF
ELEMENTS
1. Atomic Radius ( Jari Atom )
2. Electron Affinity ( Afinitas Elektron )
3. Ionization Energy ( Energi Ionisasi )
4. Electronegativity ( Keelektronegatifan )
5. Metallic Properties ( Logam & Non-
Logam)
6. Reactivity ( Kereaktifan )
7. Boiling & Melting Point (Titik Didih &
Leleh)
Chemical
Properties
Physical
Properties

3. Atomic Radius
Nuclei
Outermost
Shell
Atomic Radius
Atomic Radius is the distance between outermost
electron (valence electron) to the nuclei of the atom

4. Atomic Radius
Increases from right to left
Increasesfromuptobottom

5. Atomic Radius
+3 2e 1e
K L
+11 2e 8e
K L M
1e
3Li
11Na
+4 2e 2e
K L
+12 2e 8e
K L M
2e
4Be
12Mg
Group IA Group IIA
Period
2
Period
3

6. Ionization Energy
Ionization Energy is the energy required to lose the
electron in forming positive ion

7. Ionization Energy
+3 2e 1e
K L
+11 2e 8e
K L M
1e
3Li
11Na
Group IA
Period
2
Period
3
Gaya tarik inti terhadap elektron
valensi kuat sehingga elektron valensi
sukar dilepaskan ( IE >> )
Gaya tarik inti terhadap elektron
valensi lemah sehingga elektron
valensi mudah dilepaskan( IE << )

8. H
Be
B
C
N
O
F
Mg
Al
Si
P
S
Cl
Ionization Energy

9.  Atom berelektron banyak dapat kehilangan satu, dua, atau
lebih elektronnya.
 Energi yang diperlukan untuk melepaskan elektron
kedua, ketiga dan seterusnya disebut energi ionisasi
kedua, ketiga dan seterusnya
Example :
Points to Note
IE 1 : Be(g) + 899 kJ Be+
(g) + e
IE 2 : Be+
(g) + 1.757 kJ Be2+
(g) + e
IE 3 : Be2+
(g) + 14.848 kJ Be3+
(g) + e
IE 4 : Be3+
(g) + 21.006 kJ Be4+
(g) + e
Valence
Electron

11. Electron Affinity
Electron Affinity is the energy involved by an atom
in gas form, after it accepts an electron to form
negative ion, ex :
Cl( g) + e Cl-
(g) H = -349 kJ/mol
Cl( g) + e Cl-
(g) + 349 kJ/mol
Mean :
• Jika 1 mol atom Cl menangkap 1 mol elektron
membentuk 1 mol ion Cl-, dilepaskan energi sebesar
349 kJ (dalam bentuk kalor)
Point to Note
- = easy to accept electron (energy realized)
+ = difficult to accept electron (energy accepted)

12. Electron Affinity
increases from left to right
Increasesfrombottomtoup

13. Electronegativity
Electronegativity is a measure of the tendency of an
atom to attract electrons to its self in a bond

14. Electronegativity
Pauling’s electronegativity scale
 The higher the value, the more electronegative
the element
 Fluorine is the most electronegative element
 It has an electronegativity value of 4.0

15. Pauling’s electronegativity scale
H
2.1
He
-
Li
1.0
Be
1.5
B
2.0
C
2.5
N
3.0
O
3.5
F
4.0
Ne
-
Na
0.9
Mg
1.2
Al
1.5
Si
1.8
P
2.1
S
2.5
Cl
3.0
Ar
-
increases from left to right
Increasesfrombottomtoup
Electronegativity

16. Metallic Properties

17. Metals versus Nonmetals

18. Reactivity
Reactivity depends on the tendency an element to lose and
accept electron in forming a compound
 The most reactivity metal is Group IA (Alkali)
 The most reactivity non-metal is Group VIIA (Halogen)METAL
Non-METAL

19. NON-
METAL
METAL
Boiling & Melting Point

20. Boiling & Melting Point
Metal (IA –IIIA)
 Titik didih dan titik lelehnya diperngaruhi kekuatan
ikatan logam
 Kekuatan ikatan logam ditentukan oleh jumlah elektron
valensi
E.Val >> ikatan logam kuat Tb dan Tm >>

21. Boiling & Melting Point
Non Metal (VA –VIIA)
 Titik didih dan titik lelehnya dipengaruhi oleh wujud dan
Ar
Ar >> Tb dan Tm >>
Semi Metal (IV)
 Titik didih dan titik leleh paling puncak karena molekul
raksasa

22. Boiling & Melting Point
Non Metal
 Titik didih dan titik lelehnya dipengaruhi oleh Ar
Ar >> Tb dan Tm >>
Metal
 Titik didih dan titik leleh dipengaruhi oleh jari – jari atom
r >> ikatan logam lemah Tb dan Tm <<