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Notes One Unit Eight Molecules. Cross Word Answers State the three laws that support the existence of atoms List the five principles of Dalton's atomic theory. Calculate the masses of atoms in amu and gram units. Describe how the atomic mass unit was chosen. Calculate Average Atomic Mass - PowerPoint PPT Presentation
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Notes One Unit EightMolecules
• Cross Word Answers• State the three laws that support the existence of
atoms • List the five principles of Dalton's atomic theory.• Calculate the masses of atoms in amu and gram
units.• Describe how the atomic mass unit was chosen.• Calculate Average Atomic Mass• Reading Assignment Two unit Two Next Class
• http://www.teachersdomain.org/special/nova/nova.physics.ato/
Laws of proportions• What is the proportion for(?)…
• H2O
• H2O2
• N2O3
• N2O5
• N2O
• N2O4
2:1
1:1
2:3
2:5
2:1
1:2
Multiple Proportions
Multiple Proportions
DefiniteProportions
Law of conservation of massDEMO NaOH/HCl phenolphthalein on a balance
NaOH(aq)+ HCl(aq) H2O(l)+ NaCl(aq)
Law of conservation of mass• 2H2(g) + 1O2(g)2H2O(l)• H= H=• O= O=• Mass is conserved!• 3H2(g) + 1N2(g)2NH3(l)• N= N=• H= H=• 2C2H6(g)+ 7O2(g) 4CO2(g) + 6H2O(l)• C= C=• H= H=• O= O=
4 42 2
2 26 6
4 41214 8
12+ 6=14
Three laws that support the existence of atoms
1. Law of definite proportions
2. E=MC2
3. Law of multiple proportions
List the five(Four?) principles of Dalton's atomic theory.• 1. All matter is made of indivisible and
indestructible atoms.
• 2. All atoms of a certain element are identical in mass and properties.
• 3. Compounds can be formed by using two or more different kinds of atoms.
• 4. A chemical reaction is a rearrangement of atoms.
Carbons Mass in amu and gram units
• 1 amu=1/12 C-12
• 1 C-12 mass = 12.00000000 amu
• 1amu = 1.66053X10-24 grams.
• 12.0000000 grams/Mole!
Mass Spectroscope
Neon gas
e-1 beam
heating element negative grid
Ne Ne+1
20Ne+121Ne+1
22Ne+1
Calculating Average Atomic Mass E amu % product
C-12 C-13
12.00000013.003355
98.901.10
= 1186.8= 14.3036905
xx
1187+ 14
1201+ 14.3
118798.90 %+ 1.10 %100.00 %
÷100.00 = 12.01amu4 sd 5 sd 4 sd1201
Notes Two Unit Two The Nucleus
• Describe the evidence for the existence of electrons and their presence in atoms.
• Explain how Rutherford's experiments led to the discovery of the nucleus.
• Discuss atoms of different elements in terms of the numbers of electrons, protons, and neutrons they contain.
Potassium Gas- K(g)e-1 Beam
To Vacuum Pump
K+1 ions
Vacuum Chamber
Magnet Face To Vacuum Pump
39K+140K+1 41K+1
K+1
K
Photographic Plate
Calculating Average Atomic Mass E amu % product
79Br
81Br 78.918337680.9162913
50.697 49.317
= 4000.922961= 3990.548738
xx
+ 3990.54000.950.697 %
+49.317 %100.014 %
÷100.014 = 79.9028136 amu5 sd 6 sd 5 sd
7991.4
7991.4
= 79.903 amu
Cathode Ray Demo
• Electrons(e-1) leave the cathode
Cathodee-1
e-1e-1 e-1
Anode
- +
Cathode Ray Devices
Van de Graff Demo
Van de Graff generator
Leyden Jar
Millikan's oil-drop experiment Charge of e-1 is equal to -1.602189 x 10-19 Coulombs.
X-ray
..
.-1
-2
(+) plate
(-) plate
perfume sprayerOil drops
0
hole
battery
Rutherford's experiments
Characteristics of atoms
Radium
Lead
Gold Foil
Microscope
Alp
ha p
article
+2 8000
10,000 atoms thick
7999 pass through
mostly empty spaceSmall(1/10,000),
42He+2
dense, andheavy
positive charge core
+79
+2
Atoms and their electrons, protons, and neutrons
Proton(P+1) + Neutrons(n0)= Mass #(Z)
A Z Element P+1 n0 Symbol Name
HydrogenH111 0Hydrogen1 1
1 2 Hydrogen 1 1 H21 Hydrogen
1 3 Hydrogen 1 2 H31 Hydrogen
8 16 Oxygen 8 8 O168 Oxygen
26 57 Iron 26 31 Fe5726 Iron
-1-2-3
-16-57
Nuclear Reactions A reaction, as in fission, fusion, or radioactive decay, that
alters the energy, composition, or structure of an atomic nucleus.
23592U + n 1
0 Xe +13554 + n1
0Sr 10038
Fission:
Fusion:10n+ 7
3Li 31H
42+ He + 1
0n
Decay:
23892 U 234 Th +90
42He Alpha Decay
23490Th 234
91Pa + 0-1 Beta Decay(e-1)
Atomic Particles
Particle Symbol ChargeMass
(g)Mass(amu)
Family
proton p+ +1 1.673 x 10-24 1.00727 baryon
neutron n0 0 1.675 x 10-24 1.00866 baryon
electron/positron
e-/e+ -1/+1 9.109 x 10-28 5.485 x 10-4 lepton
neutrino 0 < 10-32 < 5 x 10-9 lepton
photon 0 0 0 photon
Notes Three Unit Eight The Structure of the Atom’s Shell
• Describe the nature of light and how it is produced. • Explain how the wavelengths of light emitted by an atom
provide information about electron energy levels. • Flame Tests Lab B
Atomic ModelRutherford model*Mostly Empty Space
Very Small,Very Dense,Positive Charged,
*Nucleus…
Where were the electrons?What are the electrons doing?
+
Particle Model of The ElectronNeils Bohr
e-1 found in the empty space.He used light to define their actions.
e-1 region
+
Electromagnetic Spectrumgamma
rayX-ray UV IR radar FM TV
Shortwave AM
Visible Light
Short wavelength
Long wavelength
Low Energy
High Energy
Bohr’s Model of the shell *Particle Model
*Circular orbits
* Hydrogen only
Light’s Energy
e-1
The Spectroscope
Helium Tube
slit
Prism
spectrograph
Bright-lineEmissionSpectrum
Solar Spectrum
• hydrogen
• helium
• mercury
• uranium
(92 elements)
Spectrum Example #1
n=1
n=2
n=3
n=4
n=5n=6
energy
RedOrange
YellowGreenBlueindgoViolet
Ground State
Excited State
Quantum Amount
Spectrum Example #2
n=1
n=2
n=3
n=4
n=5n=6
energy
RedOrange
YellowGreenBlueindgoViolet
Ground State
Excited State
Quantum Amount
Spectrum Example #3
n=1
n=2
n=3
n=4
n=5n=6
energy
RedOrange
YellowGreenBlueindgoViolet
Ground State
Excited State
Quantum Amount
Spectrum Example #4
n=1
n=2
n=3
n=4
n=5n=6
energy
RedOrange
YellowGreenBlueindgoViolet
Ground State
Excited State
Quantum Amount
Identifying Elements with Flame Tests
Na K Li Ba
Notes Four Unit Eight Electron Arrangements Forelements
• Compare the atomic models of Rutherford and Bohr. • Describe the quantum mechanical interpretation of electrons in
atoms. • State Pauli's exclusion Principle, the aufbau principle, and
Hund's rule, and describe their roles in determining the electron configuration of atoms.
Atomic ModelRutherford model*Mostly Empty Space
Very Small,Very Dense,Positive Charged,
*Nucleus…
Where were the electrons?What are the electrons doing?
+Quantum Amount
Bohr model
De Broglie’s Wave model for Electrons• Wave Nature
• Different solutions for e-1 actions.
• e-1’s act as a particle or a wave.
• e-1’s absorb or release Quantum Amount of NRG.
• Demo of waves on a string
Standing Waves
S Orbital
X-axis
y-axis
z-axis
p Orbitals Shapes
x-axis
z-axis
y-axis
p Orbitals Assembled
x-axis
z-axis
y-axis
Quantum Model for The Shell of The Atom
Electron Order of FillingAufbau principle fill the lowest energy level first
Orbital Filling Diagram
• Write the orbital filling diagram for Ne.
• How many electrons does Ne have?
• Final Answer
• Short Hand Answer
10 e-1
1s22s22p6
[He]2s22p6
attract
Orbital Filling Diagram
• Write the orbital filling diagram for Na.
• How many electrons does Na have?
• Final Answer
• Short Hand Answer
11 e-1
1s22s22p6
[Ne]3s1
3s1
Orbital Filling Diagram
• Write the orbital filling diagram for Cl.
• How many electrons does Cl have?
• Final Answer
• Short Hand Answer
17 e-1
1s22s22p63s23p5
[Ne]3s23p5
Notes Five Unit Eight
• Electron Dot diagrams • Quantum Numbers
Electron Dot Diagram for Neon
[He]2s22p6
Ne●●
● ●●●
● ●
Electron Dot Diagram for Sodium
[Ne]3s1
Na●
Electron Dot Diagram for Chlorine
[Ne]3s23p5
●●
● ●●●
●Cl
Quantum Numbers• Addresses for electrons
• Four numbers for each address
• No two addresses are the same
First number is n =1 , 2 , 3 , 4 , 5 , 6 , 7 (DistanceFrom the
Nucleus)Second number is l = 0 , 1, 2 , 3s p d f
Third number is ml = 0 = +1, 0, -1 = +2, +1, 0, -1, -2= +3, +2, +1, 0, -1, -2 , -3
p orbitald orbital
f orbitalForth number is ms = +1/2 or -1/2
s orbital
NodalPlane
P orbital Nodal planes (l=0)
X-axis
y-axis
z-axis
?
P orbital Nodal planes (l=1)
x-axis
z-axis
y-axis
x
y
z
Nodal planes (l=2)
n= l= ml = ms =3 2 -2 +1/2
Quantum Numbers
l = 0(s), 1(p), 2(d), 3(f) =
ms = +1/2 or -1/2=
n= l= ml = ms =3 1 0 -1/2
Quantum Numbers
l = 0(s), 1(p), 2(d), 3(f) =
ms = +1/2 or -1/2=
n= l= ml = ms =7 0 0 +1/2
Quantum Numbers
l = 0(s), 1(p), 2(d), 3(f) =
ms = +1/2 or -1/2=
n= ml = ms =4 3 +2 -1/2l=
Quantum Numbers
Quantum Number for Last e-1 in In
n=5 l= 1 ml=+1 ms=+1/2
Many e-1 does In have?49 e-1
Short hand element?KrMany e-1 does Kr have?36 e-1
How many e-1 to account for?13 e-1
Quantum #’s for Last e-1
Short-hand fills to where?Fill-in Valence13 e-1
