Chapter 11 Chapter 11Chapter 11Chapter 11Chapter 11Chapter 11Chapter 11Chapter 11
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Transcript of Chapter 11
![Page 1: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/1.jpg)
Chapter 11
Electrons in Atoms
![Page 2: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/2.jpg)
Greek Idea Democritus and
Leucippus Matter is made up
of indivisible particles
Dalton - one type of atom for each element
![Page 3: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/3.jpg)
Thomson’s Model
Discovered electrons Atoms were made of
positive stuff Negative electron
floating around “Plum-Pudding”
model
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Rutherford’s Model Discovered dense
positive piece at the center of the atom
Nucleus Electrons moved
around Mostly empty
space
![Page 5: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/5.jpg)
Bohr’s Model Why don’t the electrons fall into the
nucleus? Move like planets around the sun. In circular orbits at different levels. Amounts of energy separate one
level from another.
![Page 6: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/6.jpg)
Bohr’s Model
Nucleus
Electron
Orbit
Energy Levels
![Page 7: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/7.jpg)
Bohr’s ModelIn
crea
sing
ene
rgy
Nucleus
First
Second
Third
Fourth
Fifth
} Further away
from the nucleus means more energy.
There is no “in between” energy
Energy Levels
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The Quantum Mechanical Model
Energy is quantized. It comes in chunks. A quanta is the amount of energy needed to
move from one energy level to another. Since the energy of an atom is never “in
between” there must be a quantum leap in energy.
Schrodinger derived an equation that described the energy and position of the electrons in an atom
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Things that are very small behave differently from things big enough to see.
The quantum mechanical model is a mathematical solution
It is not like anything you can see.
The Quantum Mechanical Model
![Page 10: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/10.jpg)
Has energy levels for electrons.
Orbits are not circular. It can only tell us the
probability of finding an electron a certain distance from the nucleus.
The Quantum Mechanical Model
![Page 11: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/11.jpg)
The atom is found inside a blurry “electron cloud”
A area where there is a chance of finding an electron.
Draw a line at 90 %
The Quantum Mechanical Model
![Page 12: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/12.jpg)
Atomic Orbitals Principal Quantum Number (n) = the
energy level of the electron. Within each energy level the complex
math of Schrodinger’s equation describes several shapes.
These are called atomic orbitals Regions where there is a high
probability of finding an electron.
![Page 13: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/13.jpg)
1 s orbital for every energy
level Spherical
shaped
Each s orbital can hold 2 electrons Called the 1s, 2s, 3s, etc.. orbitals.
S orbitals
![Page 14: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/14.jpg)
P orbitals Start at the second energy level 3 different directions 3 different shapes Each can hold 2 electrons
![Page 15: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/15.jpg)
P Orbitals
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D orbitals Start at the third energy level 5 different shapes Each can hold 2 electrons
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F orbitals Start at the fourth energy level Have seven different shapes 2 electrons per shape
![Page 18: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/18.jpg)
F orbitals
![Page 19: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/19.jpg)
Summary
s
p
d
f
# of orbitals
Max electrons
Starts at energy level
1 2 1
3 6 2
5 10 3
7 14 4
sublevel
![Page 20: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/20.jpg)
By Energy Level First Energy Level only s orbital only 2 electrons 1s2
Second Energy Level
s and p orbitals are available
2 in s, 6 in p 2s22p6
8 total electrons
![Page 21: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/21.jpg)
By Energy Level Third energy level s, p, and d
orbitals 2 in s, 6 in p, and
10 in d 3s23p63d10
18 total electrons
Fourth energy level
s,p,d, and f orbitals
2 in s, 6 in p, 10 in d, ahd 14 in f
4s24p64d104f14
32 total electrons
![Page 22: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/22.jpg)
By Energy Level Any more than
the fourth and not all the orbitals will fill up.
You simply run out of electrons
The orbitals do not fill up in a neat order.
The energy levels overlap
Lowest energy fill first.
![Page 23: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/23.jpg)
Incr
easi
ng e
nerg
y
1s
2s
3s
4s
5s6s
7s
2p
3p
4p
5p
6p
3d
4d
5d
7p 6d
4f
5f
![Page 24: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/24.jpg)
Electron Configurations The way electrons are arranged in
atoms. Aufbau principle- electrons enter the
lowest energy first. This causes difficulties because of the
overlap of orbitals of different energies. Pauli Exclusion Principle- at most 2
electrons per orbital - different spins
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Electron Configuration Hund’s Rule- When electrons occupy
orbitals of equal energy they don’t pair up until they have to .
Let’s determine the electron configuration for Phosporus
Need to account for 15 electrons
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The first to electrons go into the 1s orbital
Notice the opposite spins
only 13 more
Incr
easi
ng e
nerg
y
1s
2s
3s
4s
5s6s
7s
2p
3p
4p
5p
6p
3d
4d
5d
7p 6d
4f
5f
![Page 27: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/27.jpg)
The next electrons go into the 2s orbital
only 11 more
Incr
easi
ng e
nerg
y
1s
2s
3s
4s
5s6s
7s
2p
3p
4p
5p
6p
3d
4d
5d
7p 6d
4f
5f
![Page 28: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/28.jpg)
• The next electrons go into the 2p orbital
• only 5 more
Incr
easi
ng e
nerg
y
1s
2s
3s
4s
5s6s
7s
2p
3p
4p
5p
6p
3d
4d
5d
7p 6d
4f
5f
![Page 29: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/29.jpg)
• The next electrons go into the 3s orbital
• only 3 more
Incr
easi
ng e
nerg
y
1s
2s
3s
4s
5s6s
7s
2p
3p
4p
5p
6p
3d
4d
5d
7p 6d
4f
5f
![Page 30: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/30.jpg)
Incr
easi
ng e
nerg
y
1s
2s
3s
4s
5s6s
7s
2p
3p
4p
5p
6p
3d
4d
5d
7p 6d
4f
5f
• The last three electrons go into the 3p orbitals.
• They each go into seperate shapes
• 3 upaired electrons
• 1s22s22p63s23p3
![Page 31: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/31.jpg)
The easy way to remember
1s2s 2p3s 3p 3d4s 4p 4d 4f
5s 5p 5d 5f6s 6p 6d 6f7s 7p 7d 7f
• 1s2
• 2 electrons
![Page 32: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/32.jpg)
Fill from the bottom up following the arrows
1s2s 2p3s 3p 3d4s 4p 4d 4f
5s 5p 5d 5f6s 6p 6d 6f7s 7p 7d 7f
• 1s2 2s2
• 4 electrons
![Page 33: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/33.jpg)
Fill from the bottom up following the arrows
1s2s 2p3s 3p 3d4s 4p 4d 4f
5s 5p 5d 5f6s 6p 6d 6f7s 7p 7d 7f
• 1s2 2s2 2p6 3s2
• 12 electrons
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Fill from the bottom up following the arrows
1s2s 2p3s 3p 3d4s 4p 4d 4f
5s 5p 5d 5f6s 6p 6d 6f7s 7p 7d 7f
• 1s2 2s2 2p6 3s2
3p6 4s2
• 20 electrons
![Page 35: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/35.jpg)
Fill from the bottom up following the arrows
1s2s 2p3s 3p 3d4s 4p 4d 4f
5s 5p 5d 5f6s 6p 6d 6f7s 7p 7d 7f
• 1s2 2s2 2p6 3s2
3p6 4s2 3d10 4p6
5s2
• 38 electrons
![Page 36: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/36.jpg)
Fill from the bottom up following the arrows
1s2s 2p3s 3p 3d4s 4p 4d 4f
5s 5p 5d 5f6s 6p 6d 6f7s 7p 7d 7f
• 1s2 2s2 2p6 3s2
3p6 4s2 3d10 4p6
5s2 4d10 5p6 6s2
• 56 electrons
![Page 37: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/37.jpg)
Fill from the bottom up following the arrows
1s2s 2p3s 3p 3d4s 4p 4d 4f
5s 5p 5d 5f6s 6p 6d 6f7s 7p 7d 7f
• 1s2 2s2 2p6 3s2
3p6 4s2 3d10 4p6
5s2 4d10 5p6 6s2
4f14 5d10 6p6 7s2
• 88 electrons
![Page 38: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/38.jpg)
Fill from the bottom up following the arrows
1s2s 2p3s 3p 3d4s 4p 4d 4f
5s 5p 5d 5f6s 6p 6d 6f7s 7p 7d 7f
• 1s2 2s2 2p6 3s2
3p6 4s2 3d10 4p6
5s2 4d10 5p6 6s2
4f14 5d10 6p6 7s2
5f14 6d10 7p6 • 108 electrons
![Page 39: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/39.jpg)
Exceptions to Electron Configuration
![Page 40: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/40.jpg)
Orbitals fill in order Lowest energy to higher energy. Adding electrons can change the
energy of the orbital. Half filled orbitals have a lower
energy. Makes them more stable. Changes the filling order
![Page 41: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/41.jpg)
Write these electron configurations
Titanium - 22 electrons 1s22s22p63s23p64s23d2
Vanadium - 23 electrons 1s22s22p63s23p64s23d3
Chromium - 24 electrons 1s22s22p63s23p64s23d4 is expected But this is wrong!!
![Page 42: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/42.jpg)
Chromium is actually 1s22s22p63s23p64s13d5
Why? This gives us two half filled orbitals. Slightly lower in energy. The same principal applies to copper.
![Page 43: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/43.jpg)
Copper’s electron configuration
Copper has 29 electrons so we expect
1s22s22p63s23p64s23d9
But the actual configuration is 1s22s22p63s23p64s13d10
This gives one filled orbital and one half filled orbital.
Remember these exceptions
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Electron configurations of Ions Ca+2 has two less electrons than Ca. Therefore the energy level diagram
must accommodate only 18 electrons (isoelectronic to Argon) instead of 20.
1s22s22p63s23p6
![Page 45: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/45.jpg)
Radiowaves
Microwaves
Infrared .
Ultra-violet
X-Rays
GammaRays
Low energy
High energy
Low Frequency
High Frequency
Long Wavelength
Short WavelengthVisible Light
![Page 46: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/46.jpg)
Atomic Spectrum
How color tells us about atoms
![Page 47: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/47.jpg)
Prism White light is
made up of all the colors of the visible spectrum.
Passing it through a prism separates it.
![Page 48: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/48.jpg)
If the light is not white By heating a gas
with electricity we can get it to give off colors.
Passing this light through a prism does something different.
![Page 49: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/49.jpg)
Atomic Spectrum Each element
gives off its own characteristic colors.
Can be used to identify the atom.
How we know what stars are made of.
![Page 50: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/50.jpg)
• These are called discontinuous spectra
• Or line spectra
• unique to each element.
• These are emission spectra
• The light is emitted given off.
![Page 51: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/51.jpg)
Light is a Particle Energy is quantized. Light is energy Light must be quantized These smallest pieces of light are
called photons. Energy and frequency are directly
related.
![Page 52: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/52.jpg)
An explanation of Atomic Spectra
![Page 53: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/53.jpg)
Where the electron starts When we write electron
configurations we are writing the lowest energy.
The energy level and electron starts from is called its ground state.
![Page 54: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/54.jpg)
Changing the energy Let’s look at a hydrogen atom
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Changing the energy Heat or electricity or light can move the
electron up energy levels
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Changing the energy As the electron falls back to ground
state it gives the energy back as light
![Page 57: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/57.jpg)
May fall down in steps Each with a different energy
Changing the energy
![Page 58: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/58.jpg)
{{{
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Further they fall, more energy, higher frequency.
This is simplified the orbitals also have different energies
inside energy levels All the electrons can move around.
Ultraviolet Visible Infrared
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The physics of the very small Quantum mechanics explains how
the very small behaves. Classic physics is what you get when
you add up the effects of millions of packages.
Quantum mechanics is based on probability because
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Heisenberg Uncertainty Principle
It is impossible to know exactly the speed and velocity of a particle.
The better we know one, the less we know the other.
The act of measuring changes the properties.
![Page 62: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/62.jpg)
More obvious with the very small
To measure where an electron is, we use light. But the light moves the electron And hitting the electron changes the frequency
of the light.
![Page 63: Chapter 11](https://reader033.fdocuments.us/reader033/viewer/2022051516/56813564550346895d9ccb38/html5/thumbnails/63.jpg)
Moving Electron
Photon
Before
ElectronChanges velocity
Photon changes wavelength
After