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Periodic Table


The Periodic Table of elements is a listing of known elements organized by their atomic number. The Periodic Table was changed over time and the order has changed to have their atomic numbers in order but also by listing them by their properties.[1]

Periods

Each row is a period of elements in which chemical properties repeat.

Periodic Law

Main article: Periodic Law

Properties of elements are periodic functions of their atomic numbers.


Periodic Trends

Main article: Periodic Trends

Trends in electronegativity

Groups

The columns are groups or families. The elements in each group have similar properties because they have the same amount of valance electrons in the outer orbital giving each of the elements their unique properties. Dimitri Mendeleev was the first to organize the periodic table.[2]


Table of Elements

Group # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Period
1 1
H

2
He
2 3
Li
4
Be

5
B
6
C
7
N
8
O
9
F
10
Ne
3 11
Na
12
Mg

13
Al
14
Si
15
P
16
S
17
Cl
18
Ar
4 19
K
20
Ca
21
Sc
22
Ti
23
V
24
Cr
25
Mn
26
Fe
27
Co
28
Ni
29
Cu
30
Zn
31
Ga
32
Ge
33
As
34
Se
35
Br
36
Kr
5 37
Rb
38
Sr
39
Y
40
Zr
41
Nb
42
Mo
43
Tc
44
Ru
45
Rh
46
Pd
47
Ag
48
Cd
49
In
50
Sn
51
Sb
52
Te
53
I
54
Xe
6 55
Cs
56
Ba
*
72
Hf
73
Ta
74
W
75
Re
76
Os
77
Ir
78
Pt
79
Au
80
Hg
81
Tl
82
Pb
83
Bi
84
Po
85
At
86
Rn
7 87
Fr
88
Ra
**
104
Rf
105
Db
106
Sg
107
Bh
108
Hs
109
Mt
110
Ds
111
Rg
112
Uub
113
Uut
114
Uuq
115
Uup
116
Uuh
(117)
(Uus)
118
Uuo

* Lanthanides 57
La
58
Ce
59
Pr
60
Nd
61
Pm
62
Sm
63
Eu
64
Gd
65
Tb
66
Dy
67
Ho
68
Er
69
Tm
70
Yb
71
Lu
** Actinides 89
Ac
90
Th
91
Pa
92
U
93
Np
94
Pu
95
Am
96
Cm
97
Bk
98
Cf
99
Es
100
Fm
101
Md
102
No
103
Lr
Atomic number colors show state at standard temperature and pressure (0 °C and 1 atm)
Solids Liquids Gases Unknown
Borders show natural occurrence
Primordial From decay Synthetic (Undiscovered)

History

Main article: History

In 1869 Russian chemist Dimitri Mendeleev arranged chemical elements by atomic mass. He predicted the discovery of other elements and left space open in his periodic table for them. [3] Mendeleyev is regarded as the primary discoverer of the periodic table. However, in 1868 (a full year before Mendeleyev), a German chemist named Lothar Meyer designed a table of elements which resembles the present periodic table. Unfortunately he did not publish this work until after the appearance of Mendeleev's first paper on the subject in 1869.[4]


Categories of Elements

Main article: Element_categories

Metals, Nonmetals, and Semimetals

Most of the periodic table is composed of metals that are on the bottom left corner of the periodic table and the top right part of the periodic table is the nonmetals and the semimetals are on the middle of the them. semimetals hve properties of metals and some properties of nonmetals, thats the reason why the semimetals are in the midle. Metals Common characteristics: Metallic luster, Generally solids at room temperature, Malleable, Ductile, Conduct heat and electricity, Combine with other metals to form alloys, Form positive ions. Nonmetals Common characteristics: Rarely have metallic luster (shine), usually gases at room temperature, Neither malleable or ductile, Poor conductors of heat and electricity, ussually are as molecules, they Combine with other nonmetals to form covalent bonds, normally form negative ions. Semimetals (Metalloids) are a class of 8 elements that have properties of both metals and nonmetals. Common characteristics are: look metallic but are brittle, neither good conductors or insulators. [5]


Major categories of Elements

Important Groups/Families of Elements

Groups are the columns of the periodic table. Elements in the same group have similar chemical properties and the same number of valence electrons. The periodic table of elements has diffent groups that have a special name like the Alkali metals (group 1), Alkaline Earth metals (group 2), the Transition metals (all the elements from group 3 to group 12), Halogens (group 17 Known as 7a),and The Noble Gases (group 18 known as 8a).


Properties of the Elements

In the periodic table there are special elements like the elements with the atomic number of 84 and up that are unstable and so they are radio active and can become a different element and release harmful particles like alpha and beta particles and gamma rays that are even mosre harmful. No element higher than 92 occur naturally, these elements are produced artificially in nuclear reactions.[6] Another type of elements is the elements in group 18 or 8a that are the noble gases that don't bond to other elements and have the electron configuration that all elements are required to have. The alkali metals all react violently in water.

The Periodic Table of Elements is a key tool for chemists.

Download

The California Reference Sheet provides a copy of the Periodic Table of the Elements during the STAR exam.

Periodic Table of Elements

Further Reading

The Comic Book Periodic Table of Elements

http://library.thinkquest.org/C006669/data/Chem/atomic/metals.html

Reference

  1. Los Alamos National Laboratory's Chemistry Division Dec 11, 2003 periodic table of elements -retreve date 2-5-09
  2. Lackman, Jon 2005 "Elemental" -retreve date 2-6-09
  3. Lenntech Periodic table history 1998 -retreive date 2/6/09
  4. Julian Trubin
  5. atomic structues: metals, nonmetals, semimetals. -retreave date 2-5-09
  6. David D. Hsu. 1996 chemicool -retreve date 2-5-09



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