The Periodic Table

Table Organization-each horizontal row is called a period (seven of them on the table)-same period=similar properties-less metallic as you move to the left on the table-vertical column is called a group or family -same group=similar properties-number of electron clouds depends on the periods-outer numbers of electrons depends on the group -eighteen groups

Periodic Law and History-Periodic="Repeating"-Properties of elements repeat -Mandeleev layed out the periodic table by atomic mass-Mosely rearranged the table by atomic number

Metals-found on the left of the table -almost empty outer clouds (makes them postive) -malleable (can be flattened)-good conductors (move heat and electricity)-ductile (can be stretched into a wire)- shiny

Nonmetals-found on the right of the table-have almost full outer clouds (become negative)-Brittle (not malleable)-poor conductors-dull and not shiny

Metalloids-found on the zigzag line on the table-also called semimetals-have a half full outer shell-shiny or dull-semiconductors

Three classes of elements:

Chemical Symbols-one or two letters-first letter is always capitallized -can come from other languages

Mosley

Mandeleev

The Periodic Table By: Christian Park Period 6

Valence Electrons: Electrons in the most outside cloud (tells if things are reactive) Group 1: Alkali Metals, very reactive (one outer electron), very low densityGroup 2: Allcaline Earth, two outer electrons, silver, more dense Group 3-12: Transition Metals, all metals, has one or two outer cloudsGroup 13-16: Subtract ten to get valence electron (includes metalloids)Group 17: Halogens, seven valence, form salts, reactiveGroup 18: Noble Gases, full cloud, unreactive Hydrogen: stands alone, one valence, very reactive