ELECTRONIC CONFIGURATION OF

MAIN GROUP ELEMENTS

( GROUP A )

ELECTRONIC CONFIGURATION

n = 1 (K)n = 2 (L)

n = 3 (M)n = 4 (N)

28

1832

Max. electron

Shell

Max electron in a shell

2 n2

With electronic configuration elements are represented numerically by the number of electrons in their shells and number of shells.

Determination of Electrons in the shell atoms

Kulit K2, jika elektron yang tersedia ≥ 2

1, hanya untuk H

Kulit L8, jika elektron yang tersedia ≥ 8

Elektron sisa, jika elektron yang tersedia< 8

Kulit M

18, jika elektron yang tersedia> 18

8, jika: 8 ≤ elektron< 18 yang tersedia

Elektron sisa, jika elektron yang tersedia< 8

Kulit N

32, jika elektron yang tersedia> 32

Elektron sisa, jika elektron yang tersedia< 8

18, jika: 18 ≤ elektron< 32 yang tersedia

8, jika: 8 ≤ elektron< 18 yang tersedia

Determination of Electrons

in the shell atomsAtomic

Number ElementsTotal electrons in Shell

K L M N O

1 Hidrogen (H) 1

2 Helium (He) 2

5 Boron (B) 2 3

8 Oxygen (O) 2 6

12 Magnesium (Mg) 2 8 2

16 Sulphur (S) 2 8 6

20 Calsium (Ca) 2 8 8 2

54 Xenon (Xe) 2 8 18 18 8

Valence electron

Valence ElectronThe electron at outermost shell

The valence electron determines the chemical characteristic of an atom

The elements that have the same valence electron, have the same chemical characteristic

ELECTRONIC CONFIGURATION

Write the electronic configuration for the following elements;

Cl

Si

Na23

11

35

17

28

14Br

35

79

b)a)

c) d)

2,8,12,8,7

2,8,4 2,8,18,7

Correlation of Electronic

Configuration with Period and GroupThe electron configuration of atom can be used to determine

an atom position in periodic table.

Group Number = valence electronPeriod Number = number of shell filled with electron

Example :Where is position the following elements

in the periodic table??

Sr38 2 8 18 8 2

Group : II A

Period : 5

Ge

32 2 8 18 4Group : IV A

Period : 4

GOL.IA : ALKALI (Except H)

GOL.IIA : ALKALINE EARTH

GOL.IIIA : BORON-ALUMINIUM

GOL.IVA : CARBON-SILICON

GOL.VA : NITROGEN-PHOSPOR

GOL.VIA : OXYGEN-SULPHUR

GOL.VIIA : HALOGEN

GOL.VIIIA : NOBLE GAS

GOL. IB-VIIIB : TRANSITION

Group in the Periodic Table

Elements in Group

Alkali (IA) : Li Na Kau Rebut Cintasuci Feri

Alkaline Earth (IIA) : Besok Minggu Cari Sri Bawa Raun

Boron - Aluminium (IIIA) : Bapak Ali Gandi India Tulen

Carbon (IVA) : Cewek Si Genit Senang Playboy

Nitrogen (VA) : Nara Pidana As Serba Bisa

Oxygen (VIA) : Orang Sinting Senang Teriak Polisi

Halogen (VIIA) : Film Charles Bronson Idaman Atun

Noble Gas (VIIIA) : Heboh Negara Arab Karna Xerangan Rumania