Struktur Atom 2014

8/11/2019 Struktur Atom 2014

1/48


2/48

Partikel ini berada dalam gerakan yang

konstan, tetapi dapat bergabung

membentuk suatu kombinasi yang mantap.

Potongan paling kecil dari materi yang tidakbisa dibagi lagi disebut atom


3/48

Melibatkan kejadian kimia

Berdasarkan asumsinya pada data

kuantitatif

Ditunjang oleh 2 percobaan ( 2 hukum alam)

Hukum kekekalan massa

Hukum perbandingan tetap


4/48

Using the Law of Conservat ion of Mass

You heat 2.53 g of metallic mercury in air, which produces 2.73 g of a red-orange residue. Assume that the chemical change is the reaction of the

metal with oxygen in air.

Mercury + oxygen red-orange residue

What is the mass of oxygen that reacts?

When you strongly heat the red-orange residue, it

decomposes to give back mercury and releases the

oxygen, which you collect.

What is the mass of oxygen you collect?


5/48

Jumlah massa zat-zat yang ada sebelumreaksi sama dengan jumlah massa zat-zat yang ada setelah reaksi


6/48

Percobaan ke

:

Sebelum

pemanasan (g

Mg)

Setelah

pemanasan (g

MgO)

Perbandingan

Mg/MgO

1 0.62 1.02 0.61

2 0.48 0.79 0.60

3 0.36 0.60 0.60


7/48

Setiap senyawa tersusun dari unsur-unsur

tertentu dengan perbandingan tetap


8/48

Tiap-tiap unsur kimia tersusun dari partikel-partikel kecilyang tidak bisa dihancurkan dan dibagi yang disebut atom.Selama perubahan kimia, atom tidak bisa diciptakan dandimusnahkan.

Semua atom dari suatu unsur mempunyai massa dan sifatyang sama, tetapi atom-atom dari suatu unsur berbedadengan atom-atom dari unsur lain, baik masa maupun sifat-sifatnya.

Dalam senyawa kimia, atom-atom dari unsur yang berlainanmelakukan ikatan dengan perbandingan numerik yangsama, exs. 1 atom A dengan 2 atom B (AB2)


9/48


10/48

8 X2Y16 X 8 Y+

2.1

Law of _________________________________


11/48

Adanya awan yang bermuatan positif dengansejumlah elektron yang terpusat yang cukup untukmenetralkan.

However, if there are electrons (-), there must be a +component.


12/48

2.2


13/48

1. atoms positive charge is concentrated in the nucleus

2. proton (p) has opposite (+) charge of electron

3. mass of p is 1840 x mass of e-(1.67 x 10-24g)

particle velocity ~ 1.4 x 107m/s

(~5% speed of light)

(1908 Nobel Prize in Chemistry)

2.2


14/48

Sebagian besar masa dan semua muatan positif terpusat

pada daerah yang sempit yang disebut inti atom nuklei)

Sebagian besar atom merupakan ruang kosong

Besarnya muatan pada inti berbeda untuk atom yang

berbeda, kira-kira setengah dari nilai numerik dari bobot

atom suatu unsur

Di luar inti suatu atom harus terdapat elektron yang

jumlahnya sama dengan satuan muatan inti


15/48

atomic radius ~ 100 pm = 1 x 10-10m

nuclear radius ~ 5 x 10-3pm = 5 x 10-15m

Rutherfords Model of

the Atom

2.2


16/48

H atoms - 1 p; He atoms - 2 p

mass He/mass H should = 2

measured mass He/mass H = 4

+9

Be1

n +12

C + energy

neutron (n) is neutral (charge = 0)

n mass ~ p mass = 1.67 x 10-24g

2.2


17/48

ParticleMass

(g)Charge

(Coulombs)Charge(units)

Electron (e-) 9.1 x 10

-28 -1.6 x 10

-19 -1

Proton (p) 1.67 x 10-24

+1.6 x 10-19

+1

Neutron (n) 1.67 x 10-24

0 0

mass p = mass n = 1840 x mass e-

2.2


18/48

ParticleMass

(g)Charge

(Coulombs)Charge(units)

Electron (e-) 9.1 x 10

-28 -1.6 x 10

-19 -1

Proton (p) 1.67 x 10-24

+1.6 x 10-19

+1

Neutron (n) 1.67 x 10-24

0 0

mass p = mass n = 1840 x mass e-

2.2


19/48

The Atom

Nucleus Electron

Shell or Orbit


20/48

The Atom Hydrogen

Proton Electron

Hydrogen has one proton, one electron and NO neutrons


21/48

The Atom Helium

ElectronProton

Neutron

Helium has two electrons, two protons and two neutrons


22/48

The Atom Helium

ElectronProton

Neutron

Helium has two electrons, two protons and two neutrons


23/48

The Atom Lithium

Protons

Neutrons

Electrons


24/48

The Atom Beryllium

Protons

Neutrons

Electrons

Beryllium has four electrons, four protons and five neutrons.


25/48

The Atom Boron

Protons

Neutrons

Electrons

Boron has five electrons, five protons and six neutrons.


26/48

The Atom Carbon

Protons

Neutrons

Electrons

Carbon has six electrons, six protons and six neutrons.


27/48

The Atom Nitrogen

Protons

Neutrons

Electrons

Nitrogen has seven electrons, seven protons and seven neutrons.


28/48

The Atom Oxygen

Protons

Neutrons

Electrons

Oxygen has eight electrons, eight protons and eight neutrons.


29/48

The Atom Fluorine

Protons

Neutrons

Electrons

Fluorine has nine electrons, nine protons and ten neutrons.


30/48

The Atom Neon

Protons

Neutrons

Electrons

Neon has ten electrons, ten protons and ten neutrons.


31/48

The Atom Sodium

Protons

Neutrons

Electrons

Sodium has eleven electrons, eleven protons and twelve neutrons.


32/48

_______________(Z) = number of protons in nucleus

______________(A) = number of protons + number of neutrons

= atomic number (Z) + number of neutrons

___________are atoms of the same element (X) with different

numbers of neutrons in the nucleus

XA

Z

H11 H (D)

21 H (T)

31

U23592 U23892

Mass Number

Atomic NumberElement Symbol

2.3


33/48

2.3


34/48

Menentukan perbandingan muatan terhadap massa (e/m)dari ion positif yang dihasilkan dalam sebuah tabung sinar

kanal

Dalam gas neon biasa kira-kira 91% dari atom-atom

mempunyai massa normal dan 9% dari atom-atom

tersebut 22/20 lebih berat dari normal.

KESIMPULAN

Atom-atom dari unsur yang sama dapat sedikit berbeda

dalam massanya

SOTOP


35/48

Symbols

Find each of these:a) number of protons

b) number of neutrons

c) number of electrons

d) Atomic number

e) Mass Number

symbol Cl

name Chlorine

atomic number 17

mass number 35.453


36/48

An____is formed when an atom, or group of atoms, has a net positive or

negative charge (why?).

_____ion with a positive charge

If a neutral atom_______one or more electrons

it becomes a cation.

_____ion with a negative charge

If a neutral atom_______one or more electrons

it becomes an anion.

Na 11 protons11 electrons Na+ 11 protons

10 electrons

Cl 17 protons

17 electronsCl-

17 protons

18 electrons

2.5


37/48

PeriodG

roup

Alkali

Metal

Noble

Gas

Ha

logen

AlkaliEarth

Metal

2.4


38/48

Naturally occurring carbon consists of three isotopes, 12C, 13C,and 14C. State the number of protons, neutrons, and electrons

in each of these carbon atoms.12C 13C 14C

6 6 6

#p _______ _______ _______

#n_______ _______ _______

#e _______ _______ _______

LecturePLUS Timberlake 38


39/48

12C 13C 14C

6 6 6

#p __6___ _ 6___ ___6___

#n __6___ _ _7___ ___8___

#e __6___ _ 6___ ___6___



40/48

Listed on the periodic table

Gives the mass of average atom of each

element compared to 12C

Average atom based on all the isotopesand their abundance %


Na22.99


41/48

Percent(%) abundance of isotopes

Mass of each isotope of that element

Weighted average =mass isotope1(%) + mass isotope2(%) +

100 100



42/48

Isotopes Mass of Isotope Abundance24Mg = 24.0 amu 78.70%

25Mg = 25.0 amu 10.13%

26Mg = 26.0 amu 11.17%

Atomic mass (average mass) Mg = 24.3 amu


Mg24.3


43/48

Gallium is a metallic element found in

small lasers used in compact discplayers. In a sample of gallium, there is

60.2% of gallium-69 (68.9 amu) atoms and

39.8% of gallium-71 (70.9 amu) atoms.What is the atomic mass of gallium?



44/48

Ga-69

68.9 amu x 60.2 = 41.5 amu for 69Ga

100

Ga-71 (%/100)70.9 amu x 39.8 = 28.2 amu for 71Ga

100

Atomic mass Ga = 69.7 amu



45/48

A sample of boron consists of 10B (mass10.0 amu) and 11B (mass 11.0 amu). If theaverage atomic mass of B is 10.8 amu,

what is the % abundance of each boronisotope?



46/48

Assign X and Y values:

X = % 10B Y = % 11B

Determine Y in terms of X

X + Y = 100Y = 100 - X

Solve for X:

X (10.0) + (100 - X )(11.0) = 10.8100 100

Multiply through by 100

10.0 X + 1100 - 11.0X = 1080



47/48

Collect X terms

10.0 X - 11.0 X = 1080 - 1100

- 1.0 X = -20

X = -20 = 20 %10

B- 1.0

Y = 100 - X

% 11B = 100 - 20% = 80% 11B



48/48

Copper has two isotopes 63Cu (62.9 amu)and 65Cu (64.9 amu). What is the %abundance of each isotope? (Hint:Check periodic table for atomic mass)

Struktur Atom 2014

Documents

Transcript of Struktur Atom 2014