S.MORRIS 2006

CONCEPT MAP

Atom Particle

(Partikel) Atomic

Nuclei (Inti Atom)

Shell(Kulit atom)

Proton

Neutron

Atomic Number(Nomor Atom)

Mass Number(Nomor Massa)

Electron

Electronic Configurat

ion

Atom Theory•Dalton’s Theory

•Thomson’s Theory

•Rutherford’s Theory

•Bohr’s Theory

HISTORY OF THE ATOMHISTORY OF THE ATOMDALTON’S ATOM THEORY

Bola pejal yang sangat kecil Partikel terkecil unsur (yang masih punya sifat unsur)

Atom unsur sama mempunyai sifat & massa sama

Atom unsur berbeda mempunyai sifat & massa beda

Tak dapat diciptakan / dimusnahkan (bukan radioaktif / bukan reaksi inti)

Atom-atom berikatan dlam suatu senyawa dengan perbandingan sederhana

HISTORY OF THE ATOMHISTORY OF THE ATOMTHOMSON’S ATOM THEORY

Kelemahan tidak dapat

menjelaskan susunan muatan positif dan negatif dalam bola atom tersebut.

Membuktikan adanya partikel lain yang bermuatan negatif dalam atom yaitu ELECTRON

HISTORY OF THE ATOMHISTORY OF THE ATOMRUTHERFORD’S ATOM THEORY

Kelemahantidak dapat

menjelaskan mengapa elektron tidak jatuh ke dalam inti atom.

atomic nuclei (inti atom)

electron

lintasan electron( Shell / kulit )

( Planet Bumi Mengelilingi Matahari )

atom tersusun dari inti atom dan elektron yang mengelilingi inti

HISTORY OF THE ATOMHISTORY OF THE ATOMBOHR’S ATOM THEORY

Kelemahantidak dapat

menjelaskan spekrum warna dari atom berelektron banyak

( Bola yang kulitnya dikelilingi banyak elektron )

Elektron berada dalam lintasannya ( ORBITAL )

ATOMIC STUCTUREATOMIC STUCTURE

ATOMIC STUCTUREATOMIC STUCTURE

Sub Atom Symbol Discoverer Charge Mass

Proton p / 1p1 Eugene Goldstein

+1 1

Electron

e / -1e0 JJ. Thomson -1 0

Neutron n / 0n1 James Chadwick 0 1

Satuannya sma

STRUCTURE OF SEVERAL ATOMSSTRUCTURE OF SEVERAL ATOMS

XAZATOMIC NUMBER & MASS NUMBERATOMIC NUMBER & MASS NUMBER

X = Symbol of ElementA = Mass NumberZ = Atomic Number

NEUTRAL ATOM

Z = proton = electron

A = proton + neutron K39

19 proton neutron

??

p = Z = 19n = A – Z = 20

Z = proton A = proton +

neutron electron = Z - charge

ION

XAZcharge

neutral atom

Cation

( + )

Anion

( - )

loss electron

gain electron

proton electron

??

F9-

p = Z = 9e = Z - charge = 9 – (-1) = 10

MASS NUMBER (A) & MASS NUMBER (A) & RELATIVE ATOMIC MASS (Ar)RELATIVE ATOMIC MASS (Ar)

Mass Number : menyatakan massa partikel dengan satuannya sma (satuan massa atom)

1 sma = 1/12 massa 1 atom C-12

1 sma = 1,66.10-24 gram

MASS NUMBER (A) & MASS NUMBER (A) & RELATIVE ATOMIC MASS (Ar)RELATIVE ATOMIC MASS (Ar)

Relative Atomic Mass :perbandingan massa rata-rata dari 1 atom suatu unsur terhadap 1/12 dari massa 1 atom 12C

Ar unsur X =

Massa 1 atom unsur X1/12 massa 1 atom 12C

Ar unsur X =

Massa 1 atom unsur X 1 sma

ExampleWhat is relative atomic mass (Ar) of magnesium (Mg), if mass of 1 magnesium atom of 4,037.10-23 gram? (1 sma = 1,66.10-24 gram)

Ar Mg = Massa 1 atom unsur Mg 1 sma

Ar Mg = 4,03710-23 gram 1,66.10-24 gram

= 24,31

ExampleWhat is mass of 5 sodium (natrium, Na) atom in sma & gram, if relative atomic mass of 1 sodium of 23? (1 sma = 1,66.10-24 gram)

Ar Na = Massa 1 atom unsur Na

1 sma

Massa 1 atom unsur Na = Ar Na x 1 sma = 23 smaMassa 5 atom unsur Na = 5 x 23 sma = 115 sma = 115 sma x 1,66. 10-24 gram

= 1,91.10-22 gram

Exercise1. What is relative atomic mass (Ar) of

oxygen (O), if mass of 1 oxygen atom of 2,657.10-23 gram?

2. Given relative atomic mass(Ar) of copper (Cu) = 63,5a.How mass of 2 copper atoms in sma?b.How mass of 1000 copper atoms in gram?

ISOTOP, ISOBAR & ISOTONISOTOP, ISOBAR & ISOTON

N147 N15

7

ISOTOP

atoms that have the same number ofprotons and electrons but have different

number of neutrons

ISOTOP, ISOTON & ISOBARISOTOP, ISOTON & ISOBAR

N147 C13

6

ISOTON

atoms that have the same number of neutrons but have different number

of protons

ISOTOP, ISOTON & ISOBARISOTOP, ISOTON & ISOBAR

N157 O15

8

ISOBAR

atoms that have the same atomic mass but have different number

of protons and neutrons

Determine Ar of Element from Determine Ar of Element from IsotopesIsotopes

Example :Klorin terdiri dari 75% isotop 35Cl dan 25% isotop 37Cl. Tentukanlah Ar dari Cl?

A r Unsur A = ( % x massa isotop A 1) + ( % x massa isotop A 2 ) 100

Ar Cl = ( % x massa isotop 35Cl ) + ( % x massa isotop 37Cl )

= { ( 75 x 35 ) + ( 25 x 37 ) } / 100 = 35,5

100

Example :

Galium terdiri atas isotop 69Ga dan 71Ga, sedangkan massa atom relatif Ga = 69,8. Tentukanlah kelimpahan (%) masing-masing isotop galium itu ?Misalkan :Kelimpahan isotop 69Ga = y % , maka kelimpahan isotop 71Ga = (100 - y)%.

( y .69) + ((100 – y).71) = 69,8

100 69 y + 7100 - 71y = 6980

-2y = -120 y = 60 Jadi, kelimpahan isotop 69Ga = 60% , isotop 71Ga = 40 %