Periodic table
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The periodic table can be understood in terms of the
possible electron states, as predicted by the solution
of the Schrödinger equation, and the Pauli principle.
for a given kind of atom (i.e. given total number of
electrons), the ground state of the atom is that in
which electrons occupy the states with the lowest
possible energy.
the electron configuration in the outer subshells of an
atom determines its chemical properties.
the beginning of every “period” of the periodic table
corresponds to the beginning of a new shell
the end of every period corresponds to the “noble
gases”, in which the outer electrons are in a
particularly stable configuration, called “noble gas
configuration”or “octet structure”.
the noble gas configuration is ns2np6 , i.e. 2 electrons in
the s subshell, and 6 electrons in the p subshell of the
shell n (except for n = 1, where there is no l = 1
subshell).
plot of ionization energy vs atomic number Z shows
minima at the Z values corresponding to the beginning
of periods (hydrogen, and the “alkali metals” Li, Na, K,
Rb, Cs), and maxima at the end of the periods (the
noble gases He, Ne, Ar, Kr, Xe, Rn).
(ionization energy = energy necessary to liberate
loosest bound electron of the atom).
Periodic table and electron configuration
1 2 3 4
5
6 7 8 9 10 11 12 13 14 15 16 17 18
1
H
He
1
2
2
Li Be
B
C
N
O
F Ne
2,1
2,3
2,4
2,5
2,6
2,7
Mg
Al Si
P
S
Cl Ar
2,8,2
2,8,3 2,8,4 2,8,5 2,8,6 2,8,7 2,8,8
Na
3 2,8,1
2,2
K Ca Sc Ti
42,8,8,
1
Cr Mn Fe Co
Ni
Cu
Zn Ga Ge As Se Br Kr
2,8,8, 2,8,9 2,8,10, 2,8,11, 2,8,13, 2,8, 2,8,1 2,8,15
2,8,1, 2,8,18 2,8,18 2,8,18 2,8,18 2,8,18
2,8,1, 2 2,8,1, 1 2,8,1, 2
2
,2
2
2
1
13,2 4,2
2
3
4
5
6
7
8
Rb Sr Y
5
V
2,8
Zr Nb Mo Tc Ru Rh Pd
2,8,1
2,8, 2,8,
2,8,18 2,8,18
2,8,18 2,8,18 2,8,18
2,8,18 2,8,18
8
18
18
8,1
8,2
10,2 12,1 13,1
16,1
18,0
9,2
14,1 15,1
Cs Ba *
Hf
Ta W Re Os Ir
Pt
Ag
Cd In Sn Sb Te
I
Xe
2,8,18
18,1
2,8,18 2,8,18 2,8,18 2,8,18 2,8,18 2,8,18 2,8,18
18,2 18,3 18,4 18,5 18,6 18,7 18,8
Au
Hg Tl Pb Bi Po At Rn
2,8,1 2,8,1
2,8,18 2,8,18
2,8,18
2,8,18 2,8,18 2,8,18 2,8,18 2,8,18 2,8,18
2,8,18
2,8,18 2,8,18 2,8,18
8
8
32,11, 32,12,
32,15,
32,18, 32,18, 32,18, 32,18, 32,18, 32,18,
32,10,2
32,13 32,1
32,17,1 32,18,1 32,18,2
2
2
2
3
4
5
6
7
8
,2
4,2
6 2,8,18 2,8,18
18,8,1 18,8,2
Fr Ra ** Rf Db Sg Bh Hs Mt Uun Uuu Uub
2,8,18, 2,8,18, 2,8,1 2,8,1 2,8,18
2,8,18,
2,8,183
2,8,183
32
32 8,32 8,32 32
2,8,1832
32
2
2
32,11, 32,12, 32,13 32,1 32,15,
32,18,1
32,10,2
32,17,1
32,18,2
2
2
2
4,2
2
2,8,18
72,8,18
32
32
18,8,1 18,8,2
La Ce Pr Nd Pm Sm Eu
Gd
Tb Dy Ho Er Tm Yb Lu
2,8,1 2,8,1
2,8,18 2,8,18 2,8,18 8
8 2,8,18 2,8,18
18,9,2 20,8,2 21,8,2 22,8, 23,8, 24,8,2 25,8,2
2
2
2,8,18
25,9,2
2,8,18 2,8,18 2,8,18 2,8,18 2,8,18 2,8,18 2,8,18
27,8,2 28,8,2 29,8,2 30,8,2 31,8,2 32,8,2 32,9,2
Ac Th Pa U Np Pu Am
Cm
Bk Cf Es Fm Md No Lr
*
**
2,8,18,
2,8,1 2,8,1
2,8,18,
2,8,18,
2,8,18 2,8,18,3
2,8,18, 2,8,18 2,8,18 2,8,18 2,8,18 2,8,18 2,8,18
32
8,32 8,32
2,8,18,32
32
32
,32
2
32
,32
,32
,32
,32
,32
,32
18,10,
21,9, 23,8,
25,9,2
18,9,2
20,9,2
24,8,2 25,8,2
26,9,2 28,8,2 29,8,2 30,8,2 31,8,2 32,8,2 32,9,2
2
2
2
Element Groups (Families)
Alkali Earth
Rare Earth
Non-Metals
Alkaline Earth
Other Metals
Halogens
Transition Metals
Metalloids
Noble Gases
Quantum numbers in periodic table
• The period indicates the value of principal quantum number
for the valence shell;
• the lanthanides and actinides are in periods 6 and 7,
respectively.
• The block indicates value of azimuthal (orbital) quantum number
l for the last subshell that received electrons in
building up the electron configuration.
• blocks are named for subshells (s, p, d, f)
• Each block contains a number of columns equal to the number of
electrons that can occupy that subshell
• The s-block (in orange) has 2 columns, because a maximum of 2
electrons can occupy the single orbital in an s-subshell.
• The p-block (in violet) has 6 columns, because a maximum of 6
electrons can occupy the three orbitals in a p-subshell.
• The d-block (in green) has 10 columns, because a maximum of 10
electrons can occupy the five orbitals in a d-subshell.
• The f-block (in dark blue) has 14 columns, because a maximum of
14 electrons can occupy the seven orbitals in a
f-subshell.
Periodic table and phases of elements
l
http://www.intercorr.com/periodic/
Periodic table
Ionization
energy
Atomic
radius
Electron
affinity
Periodic table
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l
http://library.thinkquest.org/3659/pertable/
“representative” metals:
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alkali metals
alkaline earth metals,
post-transition metals
metals
l
l
Transition metals
inner transition metals (rare earth metals) (Lanthanide, Actinide
series)
Metalloids, non-metals
l
Metalloids
l
Non-metals
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H
halogens
noble gases