Download Chapter 5 * Models of the Atom

Chapter 5 – Models of the Atom
• Do Now – Current Events and Chemistry
• Objective – Chap 4 Review
5.1 Models of the Atom
• Homework – Pg. 132 # 1-6
Supersonic Man
How does this relate to
anything we have talked
about already this year?
Write you idea in your notes
Tevatron
CERN Super Collider
Review Questions – Pg 125 # 1-9
Review Questions – Pg 125 # 1-9
1. C
2. A
3. B
4. B
5. 9
6. E
7. False, True
8. True, False
9. True, True – Correct explanation
Review what we know
Democritus
Dalton
Thompson
Rutherford
The Bohr Model
Carbon
Magnesium
Silicon
Fluorine
Do Now –Draw Bohr Models of K, O, and Ar
Any old work to turn in?
Objective – 5.1 and 5.2 The Quantum
Mechanical Model
Homework – Pg 136 # 10-13
The Electron Cloud Model
Where is the propeller?
The Quantum Mechanical Model
• The Quantum Mechanical Model determines
the allowed energies an electron can have and
how likely it is to find the electron in various
locations around the nucleus.
Atomic Orbitals
• Atomic Orbitals are thought of a regions of
space around a nucleus where a given
electron is likely (90%) to be.
• Do Now – Check neighbor’s homework and
give an effort grade of √-, √, √+
• Objective – Electron Configuration in Atoms
• HW - Pg 136 # 10-13
Pg 132 # 1-6
1. It couldn’t explain why metals give of characteristic
colors when heated or explain the chemical properties of
elements.
2. An electron is found only in a specific path or orbital
around the nucleus
3. It determines allowed energies and where it is likely to
be located.
4. The have different shapes.
5. By gaining or losing a quantum of energy.
6. In an atom, electrons have certain fixed energy levels.
To move to a different level requires the emission or
absorption of an exact amount of energy or quantum.
The energy of the electron is said to be quantized.
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Calculations
Average Mass
Total Mass (g) / Number in Sample = Average Mass (g)
A-Regular
15.10 g / 17 = .8882g
B-Peanut
=2.6078g
C-Pretzel
=2.4417g
Total
=1.7861g
Relative Abundance
Number in Sample / Total Number of Particles = Relative Abundance
A-Regular
17 / 38 =0.4474
B-Peanut
= 0.2368
C-Pretzel
= 0.3158
Total
= 1.0
Percent Abundance
Relative Abundance x 100 = Percent Abundance
A-Regular
0.4474 x 100 = 44.737 %
B-Peanut
=23.68 %
C-Pretzel
= 31.58 %
Total
= 100 %
Review of 5.1
Principal
Energy Levels
Number of
Sublevels
Orbitals
1
1
1 s (1 orbital)
2
2
2 s (1 orbital), 2 p (3 orbitals)
3
3
3 s (1 orbital,) 3 p (3 orbitals), 3 d (5 orbitals)
4
4
4 s (1 orbital,) 4 p (3 orbitals), 4 d (5 orbitals),
4 f (7 orbitals)
Chlorine has 17 electrons
1s2 2s2 2p63s23p5
Electron Configuration
• How atoms are arranged to get the most
stable atom possible.
Three Rules
1. Aufau Principle
2. Pauli Exclusion Principle
3. Hund’s Rule
Aufbau Principle
Electrons will occupy the orbitals of the lower
energy levels first.
Pauli Exclusion Principle
An orbital may describe 2 electrons, in other
words, orbitals can hold 2 electrons
If two electrons occupy the same orbital they
must have opposite spins ↑↓
Hund’s Rule
Electrons will occupy orbitals of the same
energy level in such a way that make the spin
direction as large as possible.
In other words, every
orbital at the same energy
level gets one electron
before any get a second
Exceptions to the Configuration Rules
What do you think would happen if an atom
were to differ from the configuration rules?
There are small differences between
the 3d and 4s energy levels and even
smaller differences between the 5f
and 6d levels
Friday, October 8th
• Do Now – Review Homework Worksheet
Get out your copy of the periodic
table
• Obj – Physics and the Quantum Mechanical
Model
• HW – Pg. 146 # 16 – 19
Lab Handout Part 1
Zinc
1s22s22p63s23p64s23d10
Magnesium
1s22s22p63s2
3p3
There are 3 electrons in the p sublevel of
the 3rd energy level.
• Neon
8A – Nobel Gas 2nd period
• Argon
8A – Nobel Gas 3rd period
• Vandium
5B –
4th period
Do Now – Get out the pre lab you wrote
Objective – 5.3 Physics and the Quantum
Mechanical Model
HW – Pg. 146 # 16-20
Light
Amplitude
Wavelength (λ)
Frequency (v)
Hertz (Hz)
C=λv
The speed of light is the product of the
wavelength and the frequency.
Light is electromagnetic radiation
Atomic Spectra
• When atoms absorb energy, the electrons
move to a higher energy level. These electrons
lose energy by emitting light when they return
to a lower energy level.
The frequencies emitted are unique
for different elements and
combinations of elements
The light emitted by an electron moving from a
higher energy level to a lower (not always
ground) has a frequency directly proportional to
the energy change of the electron.
Spectrum
Atomic Spectrum
Quantum Mechanics
Heisenberg Uncertainty Principle
It is impossible to know exactly
both the velocity and position
of a particle (electron) at the
same time.
Flame Test Lab
• Do Now – Pre-labs out with pen/pencil and
calculator. All bags away and table clear.
• Obj – Flame Test Lab
• HW – Pg. 153
# 1-18
Calculations
∆E = h c
λ (note that this is in m and not nm)
Calculations
∆E = h c
λ (note that this is in m and not nm)
You need to convert from nm to m.
Calcium was orange with frequency of 600nm
600 nm · 1
m =
1 x 109 nm
can you do
this ?
Understand Scientific
Notation
600 x 1/ 1 x 109
Means move decimal 9 places
to the right. Think about how
little of a meter you will have
if you only have 600 nm.
000000000000600.0000000
move 9 places
.000000600 m
or 6.0 x 10-7
Understand Scientific
Notation
How to Use Your
Calculator
600 x 1/ 1 x 109
Means move decimal 9 places
to the right. Think about how
little of a meter you will have
if you only have 600 nm.
600 x 1/ 1 x 109
600
1
1
2nd
EE
9
0r
000000000000600.0000000
move 9 places
.000000600 m
or 6.0 x 10-7
600
1
= 6 E -7
10
or 6.0x 10-7
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