Transcript the principle quantum number

Maximum Number of Electrons
• the formula 2n2 is used to find the max. # of e- on any energy level.
- n = the energy level = (row on P.T.)
• Ex…
• energy level 3… 2(3)2 = 18 e• energy level 6… 2(6)2 = 72 e-
Quantum numbers
• Principal Quantum Numbers
• Map to determine location of the
electrons…..
• (Methods for denoting earrangement for an atom: orbital
notation)
Quantum Numbers
• the ‘address’ of an e-.
• there are four quantum numbers (actually letters)...
1st = n = energy level of the e-.
- ‘the principle quantum number’
- represented by rows on the periodic table
- 1 = lowest, 7 = highest
2nd = l = shape of sub-orbital
- 4 different shapes…found on each energy level
3rd = m = orientation of orbital in space.
- which axis the orbital lies on
4th = s = spin of the e- on its axis.
- clockwise or counter-clockwise
1st Quantum Number
• 1. Principal Quantum Number
(n) – Describes the size and
energy of an orbital
•
↑n ↑E ↑Distance from nucleus
& ↓stability
•
Ex. n=1
nd
2
Quantum Number
• l = shape of orbital
• there are four orbital shapes, represented by letters…
• each orbital can only hold 2 e-.
• s = sphere = 1 orbital = 2 total e- lowest energy
• p = dumbbell = 3 orbitals = 6 total e-
• d = clover-leaf = 5 orbitals = 10 total e• f = double clover-leaf = 7 orbitals = 14 total e- highest energy
2nd Quantum number
cont.
• 2. Azmithual quantum number
(l)- describes the subshell of
the orbital
•
•
l=n–1
if l = 0 then the electron is in the
s subshell
•
•
•
l=1
l=2
l=3
p subshell
d subshell
f subshell
rd
3
Quantum number
• 3. Magnetic (ml) – describes
the 3 dimensional orientation
of an orbital
•
•
•
Values of ml = -l to +l
Ex. if l = 0 then ml = just one
orbital
If l = 1 then ml = 3 orbitals (-1, 0,
1 = x, y, z)
Orbitals
‘s’ orbital
‘p’ orbitals
Orbitals
‘d’ orbitals
‘f’ orbitals
th
4
Quantum number
• 4. Spin (ms) – describes the
electron’s intrinsic magnetism
•
•
+ ½ (spin up) or – ½ (spin down)
each e- occupies the lowest
energy orbital available
SPDF blocks in periodic table
•
Quantum Numbers Practice
• What are the 4 quantum
numbers of:
•
•
•
•
•
•
The
The
The
The
The
The
last electron in P
5th electron in Na
9th electron in Cl
5th electron in O
last electron in Cu
last electron in Fe