The periodic table
An ELEMENT is a substance that consists of atoms of one
type only. The 92 elements that occur naturally, and the 17
elements created artificially, are often arranged into a chart
called the periodic table. Each element is defined by its
atomic number- the number of protons in the nucleus of
each of its atoms (it is also the number of electrons present).
Atomic number increases along each row. (period) and
down each column(group). The shape of the table is
determined by the way in which electrons arrange
themselves around the nucleus : the positioning of
elements in order of increasing atomic number brings
together atoms with a similar pattern of orbiting electrons
(orbitals). These appear in blocks. Electrons occupy shells
of a certain energy (see pp. 308-309). Periods are ordered
according to the filling of successive shells with electrons,
while groups reflects the number of electrons in the outer
shell (valency electrons). These outer electrons are
important-they decide the chemical properties of the atom.
Elements that appear in the same group have similar
properties because they have the same number of
electrons in their outer shell. Elements in Group 0 have
"filled shells", where the outer shell holds its maximum
number of electrons and are stable. Atoms of Group I
elements have just one electrons in their outer shell. This
makes them unstable - and ready to react with other
substance.
Automic Number
21
BP in 0C
0
MP in C
Densitying cm -3
Electronegativity
Group I
1
-252.87
-259.2
0.0899
2.2
1.0
-1, 1
Atomic number is
number of protons
in each nucleus
H
Group II
1S¹
Hydrogen
3
1347
180.5
0.54
1.0
6.9
1
Li
(He)2s¹
Lithium
23.0
11
1
882.9
97.81
0.97
1
(Ne)3s¹
Sodium
39.1
19
1
774
63.65
0.86
0.90
(Ar)4s¹
Potassium
85.5
37
1
688
38.89
1.5
0.9
(Kr)5s¹
Rubidum
132.9
55
1
678.4
28.40
1.9
0.90
(Xe)6s¹
Cesium
87 (223.0)
1
(677)
(27)
0.90
(Rn)7s¹
Francium
Na
K
Rb
Cs
Fr
4
9.0
2
2970
1278
1.85
1.5
45.0
3
2831
1541
3.0
1.2
(Ar)3d¹ 4s²
Scandium
Oxidation State
Sc
Chemical Symbol
Electronic
Configuration
DIAMOND
RELATIVE ATOMIC MASS
Atomic mass (formerly atomic
weight) is the mass of each atom
of an element. It is equal to the
number of protons plus the
number of neutrons (electrons
have negligible mass). The figures
given are the averages for all the
different versions (isotopes) of
each element, measured relative
to the mass of carbon-12.
Atomic number
goes up by one
along each
period
Group III
GRAPHITE
Ca
Sr
1st transition metals
21
45.0
3
2831
1541
3.0
1.2
(Ar)3d¹4s²
Scandium
88.9
39
3
3338
(1522)
4.5
1.1
(Kr)4d¹5s²
Yttrium
57-71
Sc
Y
Ba
22
47.9
3.4
3287
1660
4.50
1.3
(Ar)3d²4s²
Titanium
91.2
40
4
4377
1852
6.51
1.2
(Kr)4d²5s²
Zirconium
178.5
72
4
4602
2227
13.28
1.2
(Xe)4f14 5d² 6s²
Hafnium
(261)
104
Ti
Zr
Hf
89-103
Ra
23
52.0
2,3,6
2672
1857
7.14
1.6
5
(Ar)3d 4s¹
Chromium
95.9
42
2,3,4,5,6
4612
2617
10.28
1.3
5
(Kr)4d 5s¹
Molybdenum
183.9
74
2,3,4,5,6
5660
3410
19.3
1.4
(Xe)4f145d46s²
Tungsten
(263)
106
-
Unp
Unh
V
Nb
Ta
Unq
Unnliquadium
24
Unnilpentium
Cr
Mo
W
25
54.9
2,3,4,6,7
1962
1244
7.43
1.6
5
(Ar)3d 4s²
Manganese
99.0
43
7
4878
2172
11.5
1.4
6
(kr)4d 5s¹
Technetium
186.2
75
2,4,7
5627
3180
21.0
1.5
(Xe)4f145d56s²
Rhenium
(262)
107
-
Mn
Tc
Re
26
55.9
2,3,6
2750
1535
7.87
1.6
6
(Ar)3d 4s²
Iron
101.8
44
3,4,8
3900
2310
(12.41)
1.4
7
(Kr)4d 5s¹
Ruthenium
190.2
76
2,3,4,6,8
5027
3045
22.57
1.5
(Xe)4f145d66s²
Osmium
(265)
108
-
Fe
Ru
Os
Uns
Unnilhexium Unnilseptium
Soft, Silvery and
highly reactive metal
Group V
58.9
2,3
2870
1495
8.9
1.7
7
(Ar)3d 4s²
Cobalt
102.9
45
1,2,3,4
3727
1966
12.39
1.5
8
(Kr)4d 5s¹
Rhodium
192.2
77
1,2,3,4,6
4130
2410
22.61
1.6
(Xe)4f145d76s²
Iridium
(266)
109
-
Co
Rh
Ir
3rd transition metals
28
58.7
2,3
2732
1453
8.91
1.8
8
(Ar)3d 4s²
Nickel
106.4
46
2,4
3140
1552
11.99
1.4
10
(Kr)4d
Palladium
195.1
78
2,4
3827
1772
21.41
1.4
(xe)4f145d96s¹
Paltinium
Ni
Pd
Pt
29
63.5
1,2
2567
1083
8.95
1.8
10
(Ar)3d 4s¹
Copper
107.9
47
1,2
2212
961.9
10.49
1.4
10
(Kr)4d 5s¹
Silver
197.0
79
1,3
2807
1064
19.32
1.4
(Xe)4f145d106s¹
Gold
Cu
AG
Au
30
65.4
2
907
419.60
7.14
1.7
10
(Ar)3d 4s²
Zinc
112.4
48
2
765
320.90
8.65
1.5
10
(Kr)4d 5s²
Cadmium
200.6
80
1,2
356.60
-38.84
13.53
1.5
(Xe) 4f145d106s²
Mercury
Zn
Cd
Hg
10.8 6
12.0
3
-4,2,4
2550
4827
(2079)
(3367)
2.35
2.26
2.0
2.5
(He)2s²2p¹
(He)2s²2p²
Boron
Carbon
27.0 14
28.1
13
3
4
2467
4
660
2355
2.70
1410
1.5
2.34
(Ne)3s²3p¹ 1.7(Ne)3s²3p²
Aluminium
Silicon
69.7 32
72.6
31
3
4
2403
2830
29.78
937.4
5.90
5.32
1.8
2.0
10
10
(Ar)3d 4s²4p¹
(Ar)3d 4s²4p²
Aluminium
Germanium
114.8 50
118.7
49
3
2,4
2080
2270
156.60
232
7.31
7.27
1.5
1.7
10
10
(Kr)4d 5s²5p¹
(Kr)4d 5s²5p²
Indium
Tin
204.4 82
207.2
81
1,3
2,4
1457
1740
303.5
327.5
11.85
11.34
1.4
1.6
(Xe)4f145d106s²6p¹ (Xe)4f145d106s²6p²
Thallium
Lead
B
C
AI
Si
Ga
Ge
In
Sn
TI
Pb
7
16.0
-2.-1
-182.96
-218.4
1.13
3.5
(He)2s²2p4
Oxygen
32.1
16
-2,2,4,6
444.67
112.8
2.1
2.4
4
(Ne)3s²3p
Sulpher
79.0
34
-2,4,6
684.9
217
4.19
2.5
(Ar)3d104s²4p4
Selenium
127.6
52
-2,4,6
990
449.5
100.25
2
10
4
(Kr)4d 5s²5p
Tellurium
84 (210.0)
2,4,6
962
254
9.14
1.8 14 10
4
(Xe)4f 5d 6s²6p
Polonium
N
O
P
S
As
Se
Sb
Te
Bi
Po
Group 0
2
Halogens
Group VII
9
19.0
-1
-188.14
-219.62
1.1
4.1
(He)2s²2p5
Fluorine
35.5
17
-1,1,3,5,7
-34.6
-100.98
1.1
2.8
5
(Ne)3s²3p
Chlorine
79.9
35
-1,1,3,5,7
58.78
-7.2
3.19
2.7
(Ar)3d104s²4p5
Bromine
126.9
53
-1,1,3,5,7
184.40
113.5
4.94
2.2
10
5
(Kr)4d 5s²5p
Iodine
85 (210.0)
-1,1,3,5,7
337
(302)
2.0
(Xe)4f145d106s²6p5
Astatine
F
CI
Br
I
At
4.0
0
-268.934
-272.2
0.178
-0
He
1s²
Helium
20.2
10
0
-246.05
-248.67
1.2
(He)2s²2p6
Neon
40.0
18
0
-185.8
-189.2
1.41
6
-(Ne)3s²3p
Argon
83.8
36
2,4
-152.30
-156.30
2.16
10
6
(Ar)3d 4s²4p
Krypton
131.3
54
2,4,6
-107.10
-111.9
3.5
10
6
(Kr)4d 5s²5p
Xenon
86 (222.0)
2
(-61.8)
(-71)
4.4
(Xe)4f145d106s²6p6
Radon
Ne
Kr
Alkaline earth
metals
Poor metals
Transition metals
Lanthanides
(rare earth)
Radioactive
metals
Semi-metals
Non-metals
Noble gases
Yellow, unreactive
precious metal
Soft, shiny,
reactive metal
GOLD
3RD TRANSITION METAL
CHROMIUM
1ST TRANSITION METAL
Xe
Rn
NOBLE GASES
Group 0contains elements
that have a filled (complete) outer
shell of electrons, which means the
atoms do not need to lose or gain
electrons by bonding with other
atoms. This makes them stable and
they do not easily form ions or react
with other elements. Noble gases are
also called rare or inert gases.
Shiny
semimetal
TIN :
GROUP 4 POOR METAL
138.9
3
3457
921
6.17
1.1
(Xe)5d¹6s²
Lanthanum
58
140.1
3,4
3426
799
6.9
1.1
(Xe)4f²6s²
Cerium
59
140.9
3,4
(3512)
931
6.5
1.1
(Xe)4f³6s²
Praseodymium
60
144.2
3
(3068)
1021
6.9
1.1
(Xe)4f46s²
Neodymium
61
147.0
3
2460
1168
1.1
Xe4F56s²
Promethium
62
150.4
2,3
1791
1077
7.54
1.1
(Xe)4f66s²
Samarium
63
152.0
2,3
1597
822
5.1
1
(Xe)4f76s²
Europium
64
157.3
3
3266
1313
8.0
1.1
(Xe)4f75d¹6s²
Gadolinium
65
89
90
91
92
93
94
95
96
La
227.0
3
3200
1050
1
(Rn)6d¹7s²
Actinium
Ac
PLUTONIUM
ACTINIDE SERIES METAL
Long
period
Unreactive, colourless gas
glows red in discharge tube
Hard,
silvery
metal
57
Actinides
Short
period
Ar
NEON :
GROUP 0
COLOURLESS GAS
ANTIMONY :
GROUP 5 SEMI-METAL
TYPES OF ELEMENT KEY :
Alkali metals
Period
p-block
Atomic mass is estimated,
as element exists fleetingly
Unniloctium Unnilennium
8
14.0
-3,2,3,4,5
-195.8
-209.86
0.81
3.1
(He)2s²2p³
Nitrogen
31.0
15
-3,3,5
280w
44.2w
1.82w
2.1
(Ne)3s²3p³
Phosphorous
74.9
33
-3,3,5
613
817
5.77
2.2
10
(Ar)3d 4s²4p³
Arsenic
121.8
51
-3,3,5
1750
630.70
6.70
1.8
10
(Kr)4d 5s²5p³
Antimony
209.0
83
3,5
1560
371.3
9.81
1.7
14
10
2
(Xe)4f 5d 6s 6p²
Bismuth
d-block
Une
Group VI
Purple-black
solid turns to
gas easily
d-block
Silvery,
reactive
metal
MAGNESIUM :
GROUP 2 METAL
27
Uno
Two series always separated out from
the table to give it a coherent shape
SODIUM
GROUP 1 METAL
CARBON POWDER
2nd transition metals
50.9
2,3,4,5
3380
1890
6.11
1.5
(Ar)3d³4s²
Vanadium
92.9
41
3.5
4742
2468
(8.57)
1.2
4
(Kr)4d 5s¹
Niobium
181.0
73
5
5425
2996
16.65
1.3
(xe)4f145d²6s²
Tantalum
(262)
105
Group IV
5
Mg
s-block
METALS AND NON-METALS
Elements at the left-hand side of each period are
metals. Metals easily lose electrons and form
positive ions. Non-metals, on the right of a period,
tend to become negative ions. Semi-metals which
have properties of both metals and non-metals,
are between the two.
ALLOTROPES OF CARBON
IODINE :
Some elements exist in
GROUP 7
more than one fromSOLID NONthese are known as allotropes.
SULPHUR
:
METAL
Carbon powder, graphite
GROUP 6 SOLID NON-METALS
and diamond are allotropes
of carbon. They all consist of
carbon atoms, but have very
Boron and
Nitrogen and
different physical properties.
carbon groups
oxygen groups
Chemical Symbol
Be
(He)2s²
Beryllium
24.3
12
2
1090
648.8
1.74
1.20
(Ne)3s²
Magnesium
40.1
20
2
1484
839
1.55
1
(Ar)4s²
Calcium
87.6
38
2
1384
769
2.63
1.0
(Kr)5s²
Strontium
137.4
56
2
1640
725
3.62
1.0
(Xe)6s²
Barium
226.0
88
2
1140
700
5.5
1.0
(Rn)7s²
Radium
Bright yellow
crystal
At. Wt.
Ce
232.0
4
4790
1750
11.7
1.1
(Rn)6d²7s²
Thorium
Th
Pr
231.0
4,5
1600
15.4
1.1
(Rn)5f²6d¹7s²
Protactinium
Pa
Nd
238.0
3,4,5,6
3818
1132
19.05
1.2
(Rn)5f³6d¹7s²
Uranium
U
Pm
237.0
3,4,5,6
3902
640
1.2
(Rn)5f46d17s2
Neptunium
Np
Sm
242.0
3,4,5,6
3232
641
1.2
(Rn)5f67s²
Plutonium
Pu
Eu
243.0
3,4,5,6
2607
994
1.2
(Rn)5f77s²
Americium
Am
Gd
247.0
3,4
1340
1.2
(Rn)5f²6d¹7s²
Curium
Cm
f-block
162.5
3
(2562)
1412
8.5
1.1
(Xe)4f106s²
DysProsium
67
97
247.0 98
251.0
3,4
3,4
1.2
(Rn)5f97s²
(Rn)5f107s²
Berkelium
Californium
99
-
1.2
158.9
3
3123
1356
8.27
1.1
(Xe)4f86s²
Terbium
Tb
Bk
66
Dy
Cf
164.9
3
2695
1474
8.8
1.1
(Xe)4f116s²
Holmium
Ho
68
167.3
3
2900
1497
9.07
1.1
(Xe)4f126s²
Erbium
Er
254.0 100 253.0
3
3
1.2
(Rn)5f117s²
(Rn)5f127s²
Einsteinium
Fermium
Es
Fm
69
168.9
2,3
1947
1545
9.33
1.1
(Xe)4f136s²
Thulium
173.0
70
2,3
1194
(819)
6.98
1.1
(Xe)4f146s²
Ytterbium
101
102
Tm
256.0
3
1.2
(Rn)5f137s²
Mendelevium
Md
Yb
71
175.0
3
(3395)
(1663)
9.84
1.1
(Xe)4f145d¹6s²
Lutetium
Lu
254.0 103 257.0
2,3
3
(Rn)5f147s²
(Rn)5f1476d¹s²
Nobelium
Lawrencium
No
No
Lr