1	PERIODIC TABLE SCIENTISTS WHO ATTEMPTED TO CLASSIFY THE ELEMENTS IN THE 19^TH CENTURY: Johann Dobereiner 1817 formed triads of elements that were similar in properties. John Newlands 1863 arranges elements in order of increasing atomic masses.
2	"Dimitri Mendeleev 1869 said properties..." Dimitri Mendeleev 1869 said properties of elements were function of their atomic masses. He arranged elements in order of their masses and elements with similar properties in horizontal rows. He predicted some of the elements that were unknown at that time. Ekasilicon.
3	"Henry Moseley arranged elements in..." Henry Moseley arranged elements in order of increasing atomic number. Proposed the Periodic Law – The chemical and physical properties of the elements are periodic functions of their atomic number.
4	PERIODIC TABLE Each horizontal row is a period. All begin with an active metal and end with a noble gas. Each vertical column in a group or family. 18 columns. The Lanthanide series begins lanthanum (no.57) The Actinide series begins with actinium (no. 89
5	OCTET RULE An atom with 8 electrons in its outer orbitals (s & p) is stable, not reactive.
6	METALS Metals are hard, shiny (luster), conduct heat and electricity, are malleable (hammered into sheets) and ductile (can be drawn into a wire). Metals have 3 or less electrons in their valence level. Metals tend to lose electrons easily in the presence or other substances.
7	"Metals" Metals
8	NONMETALS Nonmetals are gases or brittle solids at room temperatures. Nonmetals have 5 or more electrons in their valence levels. Nonmetals tend to gain electrons
9
10	METALLOIDS Metalloids are also called semimetals. Metalloids have properties of both metals and nonmetals. Metalloids touch the red line on the periodic table.
11	GROUP I ELEMENTS Group I are called alkali metals (except hydrogen). of alkali metals: Characteristics React with water to form an alkali Found in nature only as compounds Very reactive because the S¹ electrons is easily lost. Will form +1 ions
12	GROUP II ELEMENTS Group II are called alkali earth metals. Characteristics of alkali earth metals: React with water to form weak alkaline solution. Found in nature as compounds. Will form +2 ions
13	GROUPS 3 –12 ELEMENTS Are known as the transitions elements. Are metals with variable properties. Most form +2 or +3 ions.
14	GROUP 13 ELEMENTS Are known as the Boron family. Form +3 ions
15	GROUP 14 ELEMENTS Known as the carbon family. Carbon is the central element in forming organic compounds. Silicon is the central element in forming silicates and silicon chips. Can form +4, +2, -2, -4 ions.
16	GROUP 15 ELEMENTS Known as the nitrogen family. Characteristics: Not very reactive elements Usually form –3 ions.
17	GROUPS 16 ELEMENTS Known as Chalcogens. Characteristics: Highly reactive nonmetals. Will form compounds with nearly every other element.
18	GROUP 17 ELEMENTS Know as the halogens. Characteristics: are active nonmetals. Fluorine in the most active of the nonmetals. Do not occur free in nature. Form –1 ions.
19	GROUP 18 ELEMENTS Are called the noble gases. Characteristics: Do not combine with other elements. Valence level is filled. Recently, Krypton and Xenon have been forced to combine.