Electron Configurations of Cations of Transition Metals

1
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 Ar4s23d6
Mn Ar4s23d5
Fe2 Ar4s03d6 or Ar3d6
Mn2 Ar4s03d5 or Ar3d5
Fe3 Ar4s03d5 or Ar3d5
8.2
2
Effective nuclear charge (Zeff) is the positive
charge felt by an electron.
Zeff Z - s
0 lt s lt Z (s shielding constant)
Zeff ? Z number of inner or core electrons
8.3
3
8.3
4
8.3
5
Atomic Radii
8.3
6
Comparison of Atomic Radii with Ionic Radii
8.3
7
8.3
8
The Radii (in pm) of Ions of Familiar Elements
8.3
9
Electron affinity is the negative of the energy
change that occurs when an electron is accepted
by an atom in the gaseous state to form an anion.
DH -328 kJ/mol
EA 328 kJ/mol
DH -141 kJ/mol
EA 141 kJ/mol
8.5
10
8.5
11
Variation of Electron Affinity With Atomic Number
(H Ba)
8.5
12
8.4
13
Variation of the First Ionization Energy with
Atomic Number
Filled n1 shell
Filled n2 shell
Filled n3 shell
Filled n4 shell
Filled n5 shell
8.4
14
General Trend in First Ionization Energies
8.4
15
Group 1A Elements (ns1, n ? 2)
8.6
16
Group 1A Elements (ns1, n ? 2)
8.6
17
Group 2A Elements (ns2, n ? 2)
8.6
18
Group 2A Elements (ns2, n ? 2)
8.6
19
Group 3A Elements (ns2np1, n ? 2)
8.6
20
Group 3A Elements (ns2np1, n ? 2)
8.6
21
Group 4A Elements (ns2np2, n ? 2)
8.6
22
Group 4A Elements (ns2np2, n ? 2)
8.6
23
Group 5A Elements (ns2np3, n ? 2)
8.6
24
Group 5A Elements (ns2np3, n ? 2)
8.6
25
Group 6A Elements (ns2np4, n ? 2)
8.6
26
Group 6A Elements (ns2np4, n ? 2)
8.6
27
Group 7A Elements (ns2np5, n ? 2)
8.6
28
Group 7A Elements (ns2np5, n ? 2)
8.6
29
Group 8A Elements (ns2np6, n ? 2)
8.6
30
Properties of Oxides Across a Period
8.6
31
Chemistry in Action Discovery of the Noble Gases
Sir William Ramsay