Periodic System Elements

1). The basis of the Non-Metal and Metal
1. raised by Lavoisier
2. The still is very simple, because the elements of the metal itself there are still many differences.

2). Law Triade Dobereiner
 raised by Johan Wolfgang Dobereiner (Germany).
 elements are grouped into three groups of elements called Triade.
 Dasarnya: similarity physics and chemical nature of these elements.

Kins of Triade :
a.Triade Litium (Li), Natrium (Na) dan Kalium (K)

Elelment Atom Mass Wujud
Li 6,94 Padat
Na 22,99 Padat
K 39,10 Padat

b. Triade Kalsium ( Ca ), Stronsium ( Sr ) dan Barium ( Ba )
c. Triade Klor ( Cl ), Brom ( Br ) dan Iod ( I )

3). Law octave Newlands
 raised by John Newlands (UK).
 elements are grouped based on the relative increase in atomic mass (Ar).
 Element-8 to have the nature of chemicals similar to the first element, the element to-9 has a similar nature with the elements to-2 ff.
 nature-nature element that is found after a regular or periodic elements called Law 8 octave.

H Li Be B C N O
F Na Mg Al Si P S
Cl K Ca Cr Ti Mn Fe

4). Mendeleev Periodic System (Short Periodic System)
 Two chemist, Lothar Meyer (Germany) and Dmitri Ivanovich Mendeleev (Russia) based on the principles of Newlands, perform classification elements.
 Lothar Meyer prefer the nature chemical elements of Mendeleev more while the increase in atomic mass.
 According to Mendeleev: attributes element is a function of periodic relative atomic mass. This means: if the elements are developed according to the relative increase in atomic mass, the specific nature will be repeated periodically.
 elements that have similar attributes are placed in a vertical column, called Group.
 The horizontal row, for the elements based on the relative increase in atomic mass and is called Period.

5). Periodic System Modern System (Periodic length)
• presented by Henry G Moseley, who argued that the nature of a periodic function of the number atomnya.
• This means: a basic element of nature is determined by the number atomnya not by its relative atomic mass (Ar).