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CHM 3010_Quantum 1 1
CHM 3010
Physical and InorganicChemistry
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Lecturers
DR. KAMALIAH SIRAT (COORDINATOR) DR. HASLINA AHMAD
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Pengenalan Diri
DR KAMALIAH SIRAT E-mail: [email protected] Pejabat: BSF 415 No. Tel: 03-89466787
Jika tiada: Tinggalkan pesanan utk temujanjipada masa lapang saya ikut jadual.
mailto:[email protected]:[email protected] -
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Untuk Setiap Tajuk: 1
Subtajuk BBelajar
UUlang
FFaham
IIngat
LLatih
MMahir
a / / / / / /
b / / / /
c / / /
Sedikit Ilmu Untuk Dikongsi(Sumber: Dr Salihan Siais)
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ASSESSMENT TECHNIQUE
No. Assessment Technique %
1. Final Exam 40
2. Class Exams / Tests 30
3. Oral Presentation/project4. Class Participation /SCL 10
5. Lab report / Quizzes 20
100
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TESTS/Exams
TEST 1 14th October 2011 Wednesday 8.30-10.00 pm Basic Quantum Chemistry, Periodic Table, Main Group
Elements
TEST 2 18 th November 2011 Wednesday 8.30 pm Chemical bonding, Chemical Equilibrium,
Thermodynamic
Final Exam the rest of the topics (and all)
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SCL/Class presentation
10 % of total marks Groups Topics
Nuclear Chemistry Gas, liquid and solid
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Soft Skill (Kemahiran Insaniah)
You will be evaluated for KIbased on somecriteria
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Get Your Lab Schedule (kump 2)
Thursday (8-12), Teaching Lab
MP 8 (Makmal 440) and MP 9 (Makmal 442) Write down your names when getting the lab schedule
You will be divided into groups for your practical class Each of you will also be given a partner Make sure you know which lab you will be in
It is compulsory for all of you to have a lab coat and
a safety glass each
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Lab Regulations:
Be on time (5 minutes earlyno excuse) Wear your lab coat throughout Wear covered shoes Use safety goggles (except those already using
glasses)
Bring your own towel/tissue papers and matches Keep the lab clean and tidy always Arrange the stools neatly before leaving the lab Abide by all the general lab rules and regulations
Listen to and obey your demonstrators
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Report Writing: Page 1:
Name, Matric No., Lab No., Demonstrators Name, Day of Practical, Date ofPractical, Lecture Group, Lecturers Name
Page 2 Course Code and Name, Title of Experiment
Theory Materials Used Procedure in points form Results / data and Discussion Conclusion Suggestions
Answers to questions References
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Experiments and Reports
For most experiments, you will be doing them inpairs.
Only one ? report is required for each experimentbut the write up should be done alternately between
the partners You have to come to each practical class, prepared
with the outline of the report to be writtenand it willbe checked by the demonstrators
You are to finish the report on the same day You have to be in the lab for three hours.
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Try Your Best in Everything You Do
Practicals in the lab Be serious Read up before coming to the lab Prepare the lab report in the proper format in your lab
report book ? including the empty table if required for youto enter your data
Once you have obtained the data, you write the discussionand the conclusion.
In case your data are not as expected, you should be able
to explain why. No copying from previous reports.
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Skema Pemarkahan Laporan:
1. Muka surat pertama yang lengkap: 2 2. Tajuk percubaan: 2 3. Tujuan / Objektif: 4 4. Alat/Radas: 5 5. Pengenalan / Teori: 5 6. Bahan Kimia: 7 7. Kaedah: 8 8. Keputusan / data (disemak betul): 12 (+ 5) 9. Pengiraan: 15 10.Perbincangan: 13 11.Langkah berjaga-jaga: 2 12.Kesimpulan: 5 13.Rujukan: 5
14.Soalan: 10 Jumlah: 100
Siapkan rangka laporan sebelum ke kelas amali
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ReferencesReference:1. Whitten, Davis, Peck and Stanley, General
Chemistry, 7th Edition, 2004 (or Sameauthors, Chemistry, 8th Edition, 2007).
2. Brady and Senese, Chemistry: Matter andits changes, 4th Edition, 2004.
3. Silberberg, Chemistry, 3rd Edition, 2003.
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Introduction
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Philosophy
Art Science
Mathematics Physics Chemistry Biology
Analytical Physical Inorganic Organic
Physical and Inorganic Chemistry : CHM 30
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From Atom to .. Element - symbol Ions - symbol, charge Molecule - formula (correct ratio) Mixture - composition, separation Compound - composition, analysis Gas Liquid
Solid Reactionstoichiometry, balanced equation
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General Features of the Atom
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Properties of the Three Key Subatomic Particles
Charge MassRelative
1+
0
1-
Absolute(C)*
+1.60218x10-19
0
-1.60218x10-19
Relative(amu)
1.00727
1.00866
0.00054858
Absolute(g)
1.67262x10-24
1.67493x10-24
9.10939x10-28
Locationin the Atom
Nucleus
Outside
Nucleus
Nucleus
Name(Symbol)
Electron (e-)
Neutron (n0)
Proton (p+)
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Electron
Outside the nucleus Negatively charged
Particle Wave
Involved in most reactions Electron transfer Electron sharing
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Basic Quantum Theory 1
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Learning Outcomes: By the end of each of these topics
the students should be able to: Basic experiments of quantum theory
1. Relate atomic emission and absorption spectra to importantadvances in atomic theory.
2. Describe wave nature of electron 3. Describe the main features of the quantum mechanical picture of
the atom. Electronic structure
4. Describe the four quantum numbers, and give possiblecombinations of their values for specific atomic orbitals Orbital concepts, Geometry of electron clouds and Heisenbergs
uncertainty principle 5. Describe the shapes of orbitals and recall the usual order of their
relative energies
Aufbau principle, Paulis exclusion principle, Hunds rule andelectron configuration 6. Write the electron configurations of atoms 7. Relate the electron configuration of an atom to its position in the
periodic table
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Chapter Goals (Whitten: Chapter 5)
The Electronic Structures of Atoms10. Electromagnetic radiation11. The Photoelectric Effect
12. Atomic Spectra and the Bohr Atom13. The Wave Nature of the Electron14. The Quantum Mechanical Picture of the
Atom
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Chapter Goals(Whitten: Chapter 5)
15. Quantum Numbers16. Atomic Orbitals17. Electron Configurations18. Paramagnetism and Diamagnetism19. The Periodic Table and Electron
Configurations
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Throughout your study of the lecture, keep in mindthe following objectives, that you should be able to:
describe the properties of light
explain how the light emitted by an atom when it is excited
explain how the theoretical model of the electronic structure ofthe atom developed
Explain the relationship between the quantum numbers and theenergies of the electron waves in an atom
Give the symbols and allowed values for the three quantumnumbers n, l, ml, s
Recognise and draw the shapes of the different orbitals
Write the electronic configuration of elemental species (atoms,ions)
Physical and Inorganic Chemistry : CHM 30
Perform the calculations involved.
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Modern Atomic TheoryATOM = nucleus (proton and neutron) and electron
For more than 3 centuries:to prove the presence of electron and nucleus
Theory of Classical Physics
Mechanics Optics Electricity Magnetic
Quantum Mechanics
Atom Molecular Structure Chemical Bonding
Physical and Inorganic Chemistry : CHM 30
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The Quantum Mechanical Model of Atom
By the late 1800s it was clear that classical physics was incapableof describing atoms and molecules
Experiments showed that electrons acted like tiny chargedparticles in some experiments and waves in others
The physics that describes object with wave/particleduality is called quantum mechanics or quantumtheory
Energy can be transferred between things as light or radiation Radiation carries energy through space aswaves or oscillations moving
outward from a disturbance
Physical and Inorganic Chemistry : CHM 30
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Electromagnetic radiation
Can you recall what is meant byElectromagnetic Radiation ?
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Electromagnetic radiation
A form of energy transferred through vacuum or medium (such
as air or glass) by means of wavelike oscillations of electric andmagnetic field. Electromagnetic waves (radiation) may be characterized by
their height or amplitude and the number that occur per second or frequency (v)
The units of frequency are the hertz (Hz)
The peak-to-peak distance is called the wavelength,
A
)second/(1s/1s1Hz1 -1
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Frequency and Wavelength
c = n
Physical and Inorganic Chemistry : CHM 30
Distinction BetweenEnergy and Matter
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Electromagnetic Radiation
The wavelength of electromagnetic radiation has thesymbol .
Wavelength is the distance from the top (crest) of one waveto the top of the next wave. Measured in units of distance such as m,cm, . 1 = 1 x 10-10 m = 1 x 10-8 cm
The frequency of electromagnetic radiation has the symbol.
Frequency is the number of crests or troughs that pass agiven point per second.
Measured in units of 1/time - s-1
)second/(1s/1s1Hz1 -1
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CHM 3010_Quantum 1 36Physical and Inorganic Chemistry : CHM 30
is inversely proportional to n. Multiplication of and n is the radiation speed (speed of light).
n = c (2.998 X 108m s-1in vacuum)
Units: (m or nm); n [number of oscillation persecond (Hz or s-1)]
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Electromagnetic Spectrum
The wavelength of electromagnetic radiation range between 10-14 mto 102 m.
Violet
Indigo
Blue
Green
Yellow
Orange
Red
Gammaray
30cm
Frequency increases
Wavelength increases
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Example 1:
X-ray emitted by Cu is measured as having 1.54 10-10 m.
What is the frequency for this radiation?
What is the frequency for yellow radiation (wavelength
of 625 nm)?
The radio frequency of Light & Easy which is
broadcasted from Bukit Jalil, Kuala Lumpur through its
FM signal at 105.7 kHz.
What is the wavelength of the radio waves expressed in
meter?
Physical and Inorganic Chemistry : CHM 30
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Example 2
Whitten 5-5: What is the frequency of green light of
wavelength 5200 ?
m105.2001
m10x1
)(5200
cc
7-10-
nn
1-14
7-
8
s105.77
m105.200
m/s103.00
n
n
c = n
1 = ? m
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Exercise 1-1
SOLUTION:PLAN:
Interconverting Wavelength and Frequency
PROBLEM: A dental hygienist uses x-rays (l= 1.00) to take a series of dentalradiographs while the patient listens to a radio station (l = 325cm)
and looks out the window at the blue sky (l= 473nm).What is the frequency (in s-1) of the electromagnetic radiation fromeach source? (Assume that the radiation travels at the speed oflight, 3.00x108m/s.)
wavelength in units given
wavelength in m
frequency (s-1 or Hz)
1 = 10-10m1cm = 10-2m1nm = 10-9m
n = c/
Use c = n
1.00A
325cm
473nm
10-10m1
10-2m1cm
10-9m1nm
= 1.00x10-10
m
= 325x10-2m
= 473x10-9m
n =3x108m/s
1.00x10-10m= 3x1018s-1
n
=
n =
3x108m/s
325x10-2m = 9.23x107
s-1
3x108m/s
473x10-9m= 6.34x1014s-1
Physical and Inorganic Chemistry : CHM 3010
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Experiments
Theories
Th diff i d b li h i h h dj li
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Figure 7.5
The diffraction pattern caused by light passing through two adjacent slits.
Indicates the wavelike nature of electromagnetic radiation
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Quanta of Energy
Black body radiation
Max Planck 1900, experiment: heating porous solid sphere, radiation emitted from dark part inside the solid. color of radiation changed from red to yellow finally white
depending on heating temperature.
He suggested that the energy of the emitted light isdiscontinuousand composed of tiny discrete packetscalled quanta. This was later called photon by Einstein.
Black body radiation (Planck) and photoelectric effect(Einstein) indicate that theelectromagnetic radiationis particle-like.
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Electromagnetic Radiation
Black body experiment by Planck: electromagnetic radiation could be viewed as a stream of tinyenergy packets or quanta we now call photons
To explain the energy spectrum it had to be assumedthat:
1. energy is quantized2. light has particle character
Plancks equation:
Energy
sJ10x6.626constantsPlanckh
hcor EhE
34-
n
E = hn
n= frequency for light
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Figure 7.6
Blackbody Radiation
DE = h n
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Photoelectric effect
Einstein observed ejection of electron when a metal
surface was subjected to light radiation. Electron wasejected only when the radiation energy exceed certainthreshold value. The energy of a photon is proportionalto its frequency. Photon was absorbed by the electron in
the metal only when the radiation frequency exceedcertain value.n threshold frequency
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The Photoelectric Effect
Light can strike the surface of some metalscausing an electron to be ejected.
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Albert Einstein (1905)
Einstein confirmed, that the energy of a photon isproportional to its frequencyand having the speed of light
both electrons and electromagnetic radiation can berepresented as either waves or particles
excited atoms can emit light
frequency intensity energy
E = mc2
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The Photoelectric Effect
What are some practical uses of the photoelectriceffect? Electronic door openers Light switches for street lights Exposure meters for cameras
Albert Einstein explained the photoelectric effect
Explanation involved light having particle-like behavior. Einstein won the 1921 Nobel Prize in Physics for this work.
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Energy of electromagnetic radiation
Energy of a photon = hn
Where h is proportionality constant known as Plancks constant (h =
6.63 X 10-34 J s)
Thus energyE = nhn where n = 1, 2, 3, ..integer.
Vibrated atom has energy of hn, 2hn, 3hn, , nhn. n is called quantumnumber.
When atom lost energy, a quantum of energy is released in form light.
2hn
3hn
hn
E ercise 1 2
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Whitten 5-6: What is the energy of a photon of
green light with wavelength 5200 ? What is theenergy of 1.00 mol of these photons?
photonperJ103.83E
)s10s)(5.77J10(6.626E
hE
s10x5.77thatknowwe5,-5ExampleFrom
19-
1-1434-
-114
n
n
kJ/mol231photon)perJ10.83photons)(310(6.022
:photonsofmol1.00For19-23
Exercise 1-2
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Electromagnetic Radiation and Motion
Molecules interact with electromagneticradiation. Molecules can absorb and emit light.
Once a molecule has absorbed light
(energy), the molecule can:1. Rotate2. Translate3. Vibrate4. Undergo Electronic transition
Describe theActions
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Electromagnetic Radiation
For water: Rotations occur in the microwave portion of spectrum. Vibrations occur in the infrared portion of spectrum.
Translation occursacross the spectrum. Electronic transitions occur in the ultraviolet portion of
spectrum.
Which movement requires the greatestenergy? Why do you say so?
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The atomic spectrum or emission spectrumis a series of individual lines called a linespectrum
Atomic SpectraElectric current excites & gives E to e-
Atoms emit energy, as e- return tolower E state
Emission and absorptionspectra of sodium atoms
Physical and Inorganic Chemistry : CHM 30
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Flametests
strontium 38Sr copper 29Cu
Relate to Lamps NormallyFound in Everyday Life
NeonSodium
Fluorescence
Physical and Inorganic Chemistry : CHM 30
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The atomic spectrum or emissionspectrum is a series of individual lines
called a line spectrum
Atomic spectra are unique for eachelement
Light emitted by
excited atoms is
comprised of a
few narrow beamswith frequencies
characteristic of
the element.
A i S d h B h A
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Atomic Spectra and the Bohr Atom
An absorption spectrumis formed byshining a beam of white light through a sampleof gas.
Absorption spectra indicate the wavelengths of light
that have been
absorbed.
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Atomic Spectra and the Bohr Atom
Atomic and molecular spectra areimportant indicators of the underlyingstructure of the species.
In the early 20th century several eminent
scientists began to understand thisunderlying structure. Included in this list are:
Niels Bohr
Erwin Schrodinger Werner Heisenberg
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Atomic Spectra and the Bohr Atom
Every element has a unique spectrum. Thus we can use spectra to identify
elements. This can be done in the lab, stars, fireworks, etc.
E l i h
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Early atomic theory
Rutherford, 1919:
nucleus of an atom contain particles with positive charge.However he did not indicate how electron is arranged aroundthe atom. According to classical physics if e- (-ve) ismotionless it will be easily attracted to the nucleus (+ve).
And if the e-
is continuously circulating the nucleus it willlose its energy and eventually spirally approach the nucleus. Thus, based on Rutherfords theory, the stability of atom is
unexplained.
-
+
Rydberg EquationEnergy & frequency, never more & never less
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Rydberg Equation
The Rydberg equation is an empirical equation that relates thewavelengths of the lines in the hydrogen spectrum(can be used to calculate all the spectral lines of hydrogen)
Atomic line spectra tell us that when an excited atom loses energy,not just any arbitrary amount can be lost
This is possible if the electron is restricted to certain energy levels The energy of the electron is said to be quantized
= RHRydberg equation -
1
1
n22
1
n12
n2 > n1, (n refers to the numbers of the energy levels in the emission spectrumof hydrogen RH is the Rydberg constant = 1.097 x 107m-1 or 109,678 cm-1
Physical and Inorganic Chemistry : CHM 30
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Figure 7.9 Three series of spectral lines of atomic hydrogen
for the visible series, n1 = 2 and n2 = 3, 4, 5, ...
Bohrs Atomic Model
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J1018.2 182
2
2
42
222
42
h
me
n
b
hn
me
b
E
The first theoretical model that successfully accountedfor the Rydberg equation was proposed in 1913 by Niels
Bohr Bohr proposed that electrons move around the nucleus along
fixed paths or orbits much like the planets moving around the sun
The orbits, labeled with the integer n, have energy This equation allows the calculation of the energy of any orbit
Bohr s Atomic Model
Physical and Inorganic Chemistry : CHM 30
Bohr Atomic Model
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Quantum staircaseContinuous (a) and discrete (b) potential energy of a tortoise.The potential energy of the tortoise in (b) is quantized.
Bohr Atomic Model
Physical and Inorganic Chemistry : CHM 30
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Atomic Spectra and the Bohr Atom
In 1913 Neils Bohr incorporated Plancksquantum theory into the hydrogen spectrumexplanation.
Here are the postulates of Bohrs theory.
1. Atom has a number of definite and discreteenergy levels (orbits) in which an electronmay exist without emitting or absorbing
electromagnetic radiation.As the orbital radius increases so does the energy1
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postulates of Bohrs theory.
2. An electron may move from one discreteenergy level (orbit) to another, but, in sodoing, monochromatic radiation is emittedor absorbed in accordance with thefollowing equation.
EE
hchEE-E
12
12
D
n
Energy is absorbed when electrons jump to higher orbits.
n = 2 to n = 4 for exampleEnergy is emitted when electrons fall to lower orbits.
n = 4 to n = 1 for example
l f B h h
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postulates of Bohrs theory.
3. An electron moves in a circular orbit aboutthe nucleus and it motion is governed bythe ordinary laws of mechanics andelectrostatics, with the restriction that the
angular momentum of the electron isquantized (can only have certain discretevalues).
angular momentum = mvr = nh/2h = Plancks constant n = 1,2,3,4,...(energy levels)v = velocity of electron m = mass of electronr = radius of orbit
Bohrs atomic model
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Bohr s atomic model
Bohr likened e around the nucleus as planet circling the sun. Electron
moves along fixed path called orbit.
+
n=1n=3 n=2
absorption
emission
Cross section of H atom. Nucleus atthe centre and electron occupies theorbit with lowest energy (n=1 for Hatom). Electron is excited to a higherlevel when energy is absorbed. The
higher levels are unstable and e dropto lower levels and energy is releasedin form of light emission.
Bohr predicted the radius of each orbit as:
rn = n2ao where ao = 0.53 (53 pm)(Bohr radius)
The series of spectral lines of atomic hydrogen
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p y g
for the visible series in hydrogen spectrum
Lyman n1 = 1 n2 = 2,3,4,,
Balmer n1 = 2 n2 = 3,4,5,,Paschen n1 = 3 n2 = 4,5,6,,Brackett n1 = 4 n2 = 5,6,7,,Pfund n1 = 5 n2 = 6,7,8,,
Physical and Inorganic Chemistry : CHM 30
Figure 7.11
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The Bohr explanation of the three series of spectral lines.
Atomic Hydrogen Spectrum
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Atomic Hydrogen Spectrum
Example
Measure the wavelength of the third line in Brackett series for atomic
hydrogen spectrum?
n1 = 4, n2 = 4 + 3
Answer : = 2166.12 nm
Balmer, n1 = 2
1 = RH 1 - 1 RH = 109 678 cm-1
22 n22
n2 = 3, = 656.4 nm
n2 = 4, = 486.3 nm
n2 = 5, = 432.4 nm
Physical and Inorganic Chemistry : CHM 30
Exercise 1-3
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CHM 3010_Quantum 1 76
Whitten 5-7: An orange line of wavelength5890 is observed in the emission spectrumof sodium. What is the energy of one photonof this orange light?
Lets do it !
Atomic Spectra and the Bohr Atom
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Atomic Spectra and the Bohr Atom
J10375.3m10890.5
m/s1000.3sJ10626.6
hchE
m10890.5
m1015890
197
834
7-10
n
m10890.5
m101
5890
7-10
n
hchE
m10890.5
m1015890 7
-10
m10890.5
m/s1000.3sJ10626.6
hchE
m10890.5
m1015890
7
834
7-10
n
Exercise 1-4
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Example 5-8. What is the wavelength of lightemitted when the hydrogen atoms energychanges from n = 4 to n = 2?
2d4
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16
1
4
1m101.097
14
1
2
1m101.097
1
n
1
n
1R
1
2nand4n
1-7
22
1-7
22
21
12
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m104.862
m102.0571
1875.0m101.0971
0625.0250.0m101.0971
7-
1-6
1-7
1-7
Atomic Spectra and the Bohr Atom
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Atomic Spectra and the Bohr Atom
Notice that the wavelength calculated from
the Rydberg equation matches the wavelengthof the green colored line in the H spectrum.
Atomic Spectra and the Bohr Atom
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p
Light of a characteristic wavelength (and
frequency) is emitted when electrons movefrom higher E (orbit, n = 4) to lower E (orbit,n = 1). This is the origin of emission spectra.
Light of a characteristic wavelength (andfrequency) is absorbed when electron jumps from
lower E (orbit, n = 2) to higher E (orbit, n= 4) This is the origin of absorption spectra.
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Absorp
tion E
m
ission
Bohrs Atomic Theory
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Successconfirmed the Rydberg equation
correctly explains the H emission spectrum (able to explain
the line spectrum of hydrogen atom and other ionic species
(such as He+, Li2+, Be3+,) with one electron.)Bohr has introduced the concept of quantum numbers and
fixed energy levels which are important step forward in atomic
theory.
made significant contribution to the development of theatomic theory (basis for the Modern Atomic Theory)
introduction to the mechanic quantum (integer)
y
Physical and Inorganic Chemistry : CHM 30
Limitations
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Limitations
not able to account for atoms with more thanone electron and all attempt to modify it fail
(not an adequate theory)
Line spectrum
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p
White light from a tungsten filament is passed through prism, it givescontinuous spectrum of colors (rainbow). However when a gas is heated, a
line spectrum is obtained which composed of lines of certain colors(wavelength). For example when hydrogen gas is heated several lines invisible range i.e. red, blue, green and violet are observed.
Balmer showed that in this range
Where n is integer
122
7 1
2
110097.1
1
mn
http://d/Dr%20Asmah/Backup/Pengajaran/Pengajaran%20lalu/I%202004-05/CHM3010/Dr%20Zul/Brady%20Chem/183729.JPGhttp://d/Dr%20Asmah/Backup/Pengajaran/Pengajaran%20lalu/I%202004-05/CHM3010/Dr%20Zul/Brady%20Chem/183729.JPGhttp://d/Dr%20Asmah/Backup/Pengajaran/Pengajaran%20lalu/I%202004-05/CHM3010/Dr%20Zul/Brady%20Chem/183729.JPGhttp://d/Dr%20Asmah/Backup/Pengajaran/Pengajaran%20lalu/I%202004-05/CHM3010/Dr%20Zul/Brady%20Chem/183729.JPG -
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The lowest energy state of an atom iscalled the ground state (an electron withn= 1 for a hydrogen atom)
Absorption and emission
of energy by the hydrogen
atom. An electron thatabsorbs energy is raised to
a higher energy level. A
particular frequency of
light is emitted when anelectron falls to a lower
energy level.
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An electron that escapes from thenucleus has infinity for its quantum numberand zero energy
Bohrs (theoretical) equation explains the(empirical) Rydberg equation
2222
22
1111
11
or
with
)(
hl
hl
lh
nnhc
b
lhnn
n
b
n
b
lh
hc
nnb
EEE
D
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CHM 3010_Quantum 1 90
The combination of constants, b/hc, has avalue which differs from the experimentally
derived value of RH by only 0.05% Bohrs efforts to develop a general theory
of electronic structure was doomed by the
wave/particle duality of electrons De Broglie suggested that the wavelength
of a particle of mass mmoving at speed v
ismv
h
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This relation provides the link between thedescription as a particle and as a wave
Heavy objects have very shortwavelengths so their matter waves and thewave properties go unnoticed
Tiny particles with small masses havelong wavelengths so their waveproperties are an important part of their
behavior Waves combine in two ways
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End of Particle Theory ofElectron
Wave Theory of Electron
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CLASSICAL THEORY
Matter
particulate,massive
Energy
continuous,wavelike
Since matter is discontinuous and particulate
perhaps energy is discontinuous and particulate.
Observation Theory
Planck: Energy is quantized; only certain valuesallowed
blackbody radiation
Einstein: Light has particulate behavior (photons)photoelectric effectBohr: Energy of atoms is quantized; photon
emitted when electron changes orbit.atomic line spectra
Figure 7.15
Summary of the major observationsand theories leading from classicaltheory to quantum theory.
Figure 7.15 continued
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Since energy is wavelike perhaps matter is wavelike
Observation Theory
deBroglie: All matter travels in waves; energy ofatom is quantized due to wave motion ofelectrons
Davisson/Germer:electron diffractionby metal crystal
Since matter has mass perhaps energy has mass
Observation Theory
Einstein/deBroglie: Mass and energy areequivalent; particles have wavelength andphotons have momentum.
Compton: photonwavelength increases
(momentumdecreases)
after colliding withelectron QUANTUM THEORY
Energy same as Matterparticulate, massive, wavelike