Periodic Table
by
Period2Alcazar
Last updated 8 years ago
Discipline:
Science Subject:
Chemical Elements
Grade:
8


Periodic TableofElements
In 1860, Demetre Mendeleev looked for a pettern in the Periodic Table. He noticed the atoms get bigger, se he arranged it by their atomic mass. Some elements were missing, so he put a "?".Later, in 1914, Henry Moseley thought that the table should be arranged by atomic number, and everything fit perfectly. It is still arranged bty atomic number today.
Periodic Law
This states that properties of an element depend on the atomic number
It got it's name because it has a regular, repeating, pattern- so its periodic
blue : metalsyellow : non-metalsgreen : metalloids
olivia w.period 2
._._._._._._._._._._._._._
Metals
-found on the left side of the periodic table-almost empty outer clouds-are malleable (can be flattened)-are good conductors of heat and electricity-are ductile (stretche into a wire)-shiny
-surround the zig zag line-half full outer clouds (4)-shiny or dull-semi-conductors
Metalloids
Table Organization
-arranged in horizontal rows called periods-arramges in vertical columns called, or families-if they are in the same period/group they have similar properties
Chemical Symbols
Non-Metals
-always capitalize the first letter the first letter-abbreviation might be in other language
-found on the right side of the tablehave almost full clouds (7)-not shinyare brittle-poor conductors
Group 2 is made up of Alkaline Earth Metals-2 outer electrons-very reactive
Group 1 is made up of Alkali Metals-1 outer electron-very reactive
Valence Electrons: electrons in the outermost cloud of an atom
Groups 17-18 are Non-Metals
There are two rows on the bottom called Lnthanides & Actinides
Groups 3-12 are Transition Metals-1 or 2 valence electrons-less reactive than Groups 1 & 2-shiny and good conductors
Group 17 are Halogens-7 outer electrons-very reactive-fom salts
Group 18 are Noble Gases-8 valence electrons-unreactive
Groups 13-16 are Metalloids
Group 13 is the Boron Group-3 outer electrons-reactivity
Group 14 is the Boron Group-4 valence electron-reactivity varies
Group 15 is the Nitrogen Group-5 outer electrons -reactivity varies
Group 16 is the Oxygen Group-6 outer electrons-reactive
subtract 10 to find valence electrons Groups 12-18
Who Arranged It
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