november 13, 2007
DESCRIPTION
November 13, 2007. Please staple both labs together and place in basket. Spectra lab 1 st , Flame test 2 nd Then review by completing the following: Name the 4 orbitals Draw the 4 orbital shapes Define an orbital - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: November 13, 2007](https://reader035.vdocuments.site/reader035/viewer/2022062410/56815c68550346895dca7b67/html5/thumbnails/1.jpg)
November 13, 20071. Please staple both labs together and place in basket.
a. Spectra lab 1st, Flame test 2nd
2. Then review by completing the following:1. Name the 4 orbitals2. Draw the 4 orbital shapes3. Define an orbital
3. Today in class, we will continue to describe electrons using the quantum mechanical model of the atom.
Homework: Important Dates:LEQ 11/29- Ch5 TestRead Ch5 11/26- E.C. due (pg 130)
Study Guide
![Page 2: November 13, 2007](https://reader035.vdocuments.site/reader035/viewer/2022062410/56815c68550346895dca7b67/html5/thumbnails/2.jpg)
Quantum Mechanical Model
From Bohr to present
![Page 3: November 13, 2007](https://reader035.vdocuments.site/reader035/viewer/2022062410/56815c68550346895dca7b67/html5/thumbnails/3.jpg)
6.5 Quantum Mechanical Atom• Electrons are outside the nucleus• Electrons can’t be just anywhere – occupy
regions of space• Knowing the location and energy of an
electron ( a wave) is limited in accuracy– Heisenberg Uncertainty Principle
• Orbitals– Regions in space where the electron is likely to be
found– Regions are described mathematically as waves
![Page 4: November 13, 2007](https://reader035.vdocuments.site/reader035/viewer/2022062410/56815c68550346895dca7b67/html5/thumbnails/4.jpg)
Schrodinger Wave EquationIn 1926 Schrodinger wrote an equation that described both the particle and wave nature of the e-
Wave function (Y) describes:1 . energy of e- with a given Y2 . probability of finding e- in a volume of space
Schrodinger’s equation can only be solved exactly for the hydrogen atom. Must approximate its solution for multi-electron systems. Solutions to wave functions require integer quantum numbers n, l and ml.
7.5
![Page 5: November 13, 2007](https://reader035.vdocuments.site/reader035/viewer/2022062410/56815c68550346895dca7b67/html5/thumbnails/5.jpg)
• Solutions to wave functions require integer quantum numbers n, l and ml
• Quantum numbers are much like an address, a place where the electrons are likely to be found
Y = fn(n, l, ml, ms)
Each distinct set of 3 quantum numbers corresponds to an orbital
![Page 6: November 13, 2007](https://reader035.vdocuments.site/reader035/viewer/2022062410/56815c68550346895dca7b67/html5/thumbnails/6.jpg)
QUANTUM NUMBERSThe shape, size, and energy of each orbital is a function
of 3 quantum numbers which describe the location of an electron within an atom or ion
n (principal) ---> energy levell (angular momentum) ---> shape of orbitalml (magnetic) ---> designates a particular suborbital
The fourth quantum number is not derived from the wave function
s (spin) ---> spin of the electron (clockwise or counterclockwise: ½ or – ½)
![Page 7: November 13, 2007](https://reader035.vdocuments.site/reader035/viewer/2022062410/56815c68550346895dca7b67/html5/thumbnails/7.jpg)
Schrodinger Wave EquationY = fn(n, l, ml, ms)
principal quantum number n
n = 1, 2, 3, 4, ….
n=1 n=2 n=3
7.6
distance of e- from the nucleus
![Page 8: November 13, 2007](https://reader035.vdocuments.site/reader035/viewer/2022062410/56815c68550346895dca7b67/html5/thumbnails/8.jpg)
e- density (1s orbital) falls off rapidly as distance from nucleus increases
Where 90% of thee- density is foundfor the 1s orbital
7.6
![Page 9: November 13, 2007](https://reader035.vdocuments.site/reader035/viewer/2022062410/56815c68550346895dca7b67/html5/thumbnails/9.jpg)
Y = fn(n, l, ml, ms)
angular momentum quantum number l
for a given value of n, l = 0, 1, 2, 3, … n-1
n = 1, l = 0n = 2, l = 0 or 1
n = 3, l = 0, 1, or 2
Shape of the “volume” of space that the e- occupies
l = 0 s orbitall = 1 p orbitall = 2 d orbitall = 3 f orbital
Schrodinger Wave Equation
7.6
![Page 10: November 13, 2007](https://reader035.vdocuments.site/reader035/viewer/2022062410/56815c68550346895dca7b67/html5/thumbnails/10.jpg)
Types of Orbitals (l)
s orbital p orbital d orbitall = 0 l = 2l = 1
![Page 11: November 13, 2007](https://reader035.vdocuments.site/reader035/viewer/2022062410/56815c68550346895dca7b67/html5/thumbnails/11.jpg)
l = 0 (s orbitals)
l = 1 (p orbitals)
7.6
![Page 12: November 13, 2007](https://reader035.vdocuments.site/reader035/viewer/2022062410/56815c68550346895dca7b67/html5/thumbnails/12.jpg)
p Orbitalsthis is a p sublevel
with 3 orbitalsThese are called x, y, and z
planar node
Typical p orbital
There is a PLANAR NODE thru the nucleus, which is an area of zero probability of finding an electron
3py orbital
![Page 13: November 13, 2007](https://reader035.vdocuments.site/reader035/viewer/2022062410/56815c68550346895dca7b67/html5/thumbnails/13.jpg)
p Orbitals
• The three p orbitals lie 90o apart in space
![Page 14: November 13, 2007](https://reader035.vdocuments.site/reader035/viewer/2022062410/56815c68550346895dca7b67/html5/thumbnails/14.jpg)
l = 2 (d sublevel with 5 orbitals)
7.6
d Orbitals
![Page 15: November 13, 2007](https://reader035.vdocuments.site/reader035/viewer/2022062410/56815c68550346895dca7b67/html5/thumbnails/15.jpg)
f OrbitalsFor l = 3 f sublevel with 7 orbitals
![Page 16: November 13, 2007](https://reader035.vdocuments.site/reader035/viewer/2022062410/56815c68550346895dca7b67/html5/thumbnails/16.jpg)
Y = fn(n, l, ml, ms)
magnetic quantum number ml
for a given value of lml = -l, …., 0, …. +l
orientation of the orbital in space
if l = 1 (p orbital), ml = -1, 0, or 1if l = 2 (d orbital), ml = -2, -1, 0, 1, or 2
Schrodinger Wave Equation
7.6
![Page 17: November 13, 2007](https://reader035.vdocuments.site/reader035/viewer/2022062410/56815c68550346895dca7b67/html5/thumbnails/17.jpg)
ml = -1 ml = 0 ml = 1
ml = -2 ml = -1 ml = 0 ml = 1 ml = 27.6
![Page 18: November 13, 2007](https://reader035.vdocuments.site/reader035/viewer/2022062410/56815c68550346895dca7b67/html5/thumbnails/18.jpg)
Y = fn(n, l, ml, ms)spin quantum number ms
ms = +½ or -½
Schrodinger Wave Equation
ms = -½ms = +½
7.6
![Page 19: November 13, 2007](https://reader035.vdocuments.site/reader035/viewer/2022062410/56815c68550346895dca7b67/html5/thumbnails/19.jpg)
Existence (and energy) of an electron in an atom is described by its unique wave function Y.
Pauli exclusion principle - no two electrons in an atomcan have the same four quantum numbers.
Schrodinger Wave EquationY = fn(n, l, ml, ms)
•Each seat is uniquely identified (E1, R12, S8)•Each seat can hold only one individual at a time
7.6
![Page 20: November 13, 2007](https://reader035.vdocuments.site/reader035/viewer/2022062410/56815c68550346895dca7b67/html5/thumbnails/20.jpg)
Schrodinger Wave EquationY = fn(n, l, ml, ms)
Shell – electrons with the same value of n
Subshell – electrons with the same values of n and l
Orbital – electrons with the same values of n, l, and ml
How many electrons can an orbital hold?
If n, l, and ml are fixed, then ms = ½ or - ½
Y = (n, l, ml, ½) or Y = (n, l, ml, -½)An orbital can hold 2 electrons 7.6
![Page 21: November 13, 2007](https://reader035.vdocuments.site/reader035/viewer/2022062410/56815c68550346895dca7b67/html5/thumbnails/21.jpg)
Summary• An electron has a 100% probability of being
somewhere• ORBITAL: The region in space where an electron is
likely to be found• The usual pictures of orbitals show the regions
where the electron will be found 90% of the time
http://www.falstad.com/qmatom/
![Page 22: November 13, 2007](https://reader035.vdocuments.site/reader035/viewer/2022062410/56815c68550346895dca7b67/html5/thumbnails/22.jpg)
7.6
Summary
![Page 23: November 13, 2007](https://reader035.vdocuments.site/reader035/viewer/2022062410/56815c68550346895dca7b67/html5/thumbnails/23.jpg)
How many 2p orbitals are there in an atom?
2p
n=2
l = 1
If l = 1, then ml = -1, 0, or +1
3 orbitals
How many electrons can be placed in the 3d subshell?
3d
n=3
l = 2
If l = 2, then ml = -2, -1, 0, +1, or +2
5 orbitals which can hold a total of 10 e-
7.6
![Page 24: November 13, 2007](https://reader035.vdocuments.site/reader035/viewer/2022062410/56815c68550346895dca7b67/html5/thumbnails/24.jpg)
Compare and contrast the Bohr and quantum mechanical models.
Summary