Transcript Document

CHAPTER 7
Quantum Theory and the Electronic Structure of Atoms
Semester 2 / 2014
7.6 Quantum Numbers
7.7 Atomic Orbital
7.8 Electronic configuration (Refer lecture)
7.9 The building-up principle
Quantum Numbers
Principal Q. No (n)
Angular momentum
n =1,2,3,4……
Magnetic Q.No (ml)
ml= -l….0, +l
Q.No (l)
Electron Spin Q.No
(ms)
Distance of e-
l=0  n-1
Orientation of the orbital ms = +
from the nucleus
Shape of the “volume”
in space
n=1
K shell
n=2
L shell
of space that the eoccupies
n=2
M shell
l
0
1
2
3 4 5
n=2
N shell
Orbital
s
p
d
f
.
.
.
.
.
.
.
.
g h
1 or  1
2
2
Example : 1 List values of n,l,ml in 2p sub shell
2p
n
l =1
i.e. n=2, l =1 , ml = -1,0,1
EXAMPLE 2 TOTAL NUMBER OF ORBITALS ASSOCIATED WITH
PRINCIPAL QUANTUM NO “2”
n=2
l =0
l =1
1
ml=0
ml=1
ml=2
ml=3
3
4
EXAMPLE 3
List different ways to write four quantum Numbers that
designate e- in A as orbital
n=4 , l=0, ml=0, ms = +
1
2
n=4, l=0, ml=0, ms= -
1
2
l = 0 (s orbitals)
7.7 Atomic Orbitals
l = 1 (p orbitals)
l = 2 (d orbitals)
7.8 Electron Configuration
Refer Chapter 2 Lecture notes
7.9 The building-up Principle
Aufbau principle : As protons are added one by one to the
Nucleus to build up the elements, electrons are similarly add
to the atomic orbitals.
Example :
Atomic
Symbol
Number
1
2
3
4
5
.
.
.
21
.
24
.
29
H
He
Li
Be
B
.
.
.
Sc
.
Cr
.
Cu
Electron Configuration
1s1
1s2
[He]2s1
[He]2s2
[He]2s22p1
.
.
.
[Ar]4s23d1
.
[Ar]4s13d5
.
[Ar]4s13d10