CHEMISTRY - DMCU 1233
Fakulti Kejuruteraan Mekanikal, UTeM
Lecturer:
IMRAN SYAKIR BIN MOHAMAD
MOHD HAIZAL BIN MOHD HUSIN
NONA MERRY MERPATI MITAN
Electronic Structure of Atoms &
Periodic Table
Chapter 4
1
Quantum Numbers
Principal quantum number – ( n )
Angular momentum quantum number – ( l )
Magnetic quantum number – ( ml )
Spin quantum number – ( ms )
2
Quantum Numbers (n, l, ml, ms)
principal quantum number n
n = 1, 2, 3, 4, ….
distance of e- from the nucleus
n=2
n=3
n=1
3
Quantum Numbers(n, l, ml, ms)
angular momentum quantum number l
for a given value of n, l = 0, 1, 2, 3, … n-1
n = 1,
n = 2,
n = 3,
l=0
l = 0 or 1
l = 0, 1, or 2
l=0
l=1
l=2
l=3
s orbital
p orbital
d orbital
f orbital
Shape of the “volume” of space that the e- occupies
4
l = 0 (s orbitals)
l = 1 (p orbitals)
5
l = 2 (d orbitals)
6
Quantum Numbers (n, l, ml, ms)
magnetic quantum number ml
for a given value of l
ml = -l, …., 0, …. +l
for l = 0 (s orbital) ml = 0
if l = 1 (p orbital), ml = -1, 0, or +1
if l = 2 (d orbital), ml = -2, -1, 0, +1, or +2
orientation of the orbital in space
7
ml = -1
ml = -2
ml = 0
ml = -1
ml = 0
ml = 1
ml = 1
ml = 2
8
Quantum Numbers (n, l, ml, ms)
spin quantum number ms
ms = +½ or -½
ms = +½ ms = -½
Q&A
Experimental
arrangement for demo
the spinning motion of
electrons
9
Quantum Numbers (n, l, ml, ms)
Existence (and energy) of electron in atom is described
by its unique Quantum Numbers
Pauli exclusion principle
No two electrons in an atom
can have the same four quantum
numbers.
10
11
Quantum Numbers (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?
12
How many 2p orbitals are there in an atom?
How many electrons can be placed in the 3d
subshell?
Q&A
13
Electron configuration is how the electrons are
distributed among the various atomic orbitals in an
atom.
1s1
principal quantum
number n
number of electrons
in the orbital or subshell
angular momentum
quantum number l
Orbital diagram
H
1s1
14
Order of orbitals (filling) in multi-electron atom
“Fill up” electrons in
lowest energy orbitals
(Aufbau principle)
1s < 2s < 2p < 3s < 3p < 4s < 3d < 4p < 5s < 4d < 5p < 6s
15
Li 3 electrons
C 6 electrons
C 1s22s22p2
B 5 electrons
B 1s22s22p1
Li 1s22s1
H 1 electron
H 1s1
16
The most stable arrangement of electrons
in subshells is the one with the greatest
number of parallel spins (Hund’s rule).
Ne 10 electrons
Ne 1s22s22p6
F 9 electrons
F 1s22s22p5
O 8 electrons
O 1s22s22p4
N 7 electrons
N 1s22s22p3
17
What is the electron configuration of Mg?
What are the possible quantum numbers for the
last (outermost) electron in Cl?
18
Outermost subshell being filled with electrons
19
Paramagnetic
unpaired electrons
2p
Diamagnetic
all electrons paired
2p
20
Q & A session
Name the orbital described by the following
quantum numbers :
a.
b.
c.
d.
n
n
n
n
=
=
=
=
3,
3,
3,
5,
l
l
l
l
=
=
=
=
0
1
2
0
21
Q & A session
Give the n and l values for the following
orbital
a. 1s
b. 3s
c. 2p
d. 4d
e. 5f
What and the possible ml values for the
following types of orbital?
a. s
b. p
c. d
d. f
22
Q & A session
How many possible orbital are there for n =
a. 4
b. 10
How many electrons can inhabit all of the
n = 4 orbital?
Place the following orbital in order of
increasing energy:
1s, 3s, 4s, 6s, 3d, 4f, 3p, 7s, 5d, 5p
23
Write electron configurations for the
following atoms:
a. H
Q & A session
b. Li+
c. N
d. Fe. Ca
24
Q & A session
Draw an orbital diagrams for atoms with
the following electron configurations:
1s22s22p63s23p3
25
Periodic
Table
26
When the Elements Were Discovered
27
4f
5f
28
ns2np6
ns2np5
ns2np4
ns2np3
ns2np2
d10
d5
d1
ns2
ns2np1
ns1
Ground State Electron Configurations of the Elements
29
Classification of the Elements
30
Electron Configurations of Cations and Anions
Of Representative Elements
Na [Ne]3s1
Ca [Ar]4s2
Al [Ne]3s23p1
Na+ [Ne]
Ca2+ [Ar]
Al3+ [Ne]
Atoms gain electrons so
that anion has a noblegas outer electron
configuration.
Atoms lose electrons so that
cation has a noble-gas outer
electron configuration.
H 1s1
H- 1s2 or [He]
F 1s22s22p5
F- 1s22s22p6 or [Ne]
O 1s22s22p4
O2- 1s22s22p6 or [Ne]
N 1s22s22p3
N3- 1s22s22p6 or [Ne]
31
-1
-2
-3
+3
+2
+1
Cations and Anions Of Representative Elements
32
Ion charges
33
Na+: [Ne]
Al3+: [Ne]
O2-: 1s22s22p6 or [Ne]
F-: 1s22s22p6 or [Ne]
N3-: 1s22s22p6 or [Ne]
Na+, Al3+, F-, O2-, and N3- are all isoelectronic with Ne
What neutral atom is isoelectronic with H- ?
34
Electron Configurations of Cations of Transition Metals
When a cation is formed from an atom of a transition metal,
electrons are always removed first from the ns orbital and then
from the (n – 1)d orbitals.
Fe: [Ar]4s23d6
Mn: [Ar]4s23d5
Fe2+: [Ar]4s03d6 or [Ar]3d6
Mn2+: [Ar]4s03d5 or [Ar]3d5
Fe3+: [Ar]4s03d5 or [Ar]3d5
35