Periodic Table

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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.<ref> Los Alamos National Laboratory's Chemistry Division Dec 11, 2003 periodic table of elements -retrieve date 2-5-09 </ref>

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.<ref> Lackman, Jon 2005 "Elemental" -retrieve date 2-6-09 </ref>

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

Element categories in the periodic table

Metals						Metalloids	Nonmetals			Unknown
Alkali metals	Alkaline earth metals	Inner transition elements		Transition elements	Other metals		Other nonmetals	Halogens	Noble gases
		Lanthanides	Actinides

**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. <ref>Lenntech Periodic table history 1998 -retreive date 2/6/09 </ref> 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.<ref>Julian Trubin</ref>

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. <ref> atomic structues: metals, nonmetals, semimetals. -retreave date 2-5-09 </ref>

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 more harmful. No element higher than 92 occur naturally, these elements are produced artificially in nuclear reactions.<ref> David D. Hsu. 1996 chemicool -retrieve date 2-5-09</ref> 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.

Atomic Radius

The atomic radius increases as you move down and left.

Ionic Radius

The ionic radius increases as you move down and left. Cation are smaller and anions are larger.

Metallic Character/Metal Reactivity

Metallic character/Metal Reactivity increase as you move down and left.

1st Ionization Energy

1st ionization energy increases as you move up and right.

Electronegativity

Electronegativity increases as you move up and right.

Nonmetallic Character/Nonmetal Reaction

Nonmetallic Character/Nonmetal Reaction increases as you move up and right.

Cation and Anions

Cations are the metals and anions are the nonmetals.

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

Reference

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