Where it all is

 1856: John Newlands discovered that elements had repeating patterns of chemical and physical properties. LAW OF OCTAVES  1869: Dmitri Mendeleev arranged the first one based on Atomic Masses and the Law of Octaves  1913: Henry Moseley Arranged the Modern Periodic Table based on Atomic Number.  1950: Glenn Seaborg developed the f block.

 Groups or Families ◦ Columns that go up and down. ◦ There are 18 Groups  Periods ◦ Rows that go across ◦ There are 7 Periods

 Highly reactive  Replace Hydrogen in Water  All have 1 valence electron  All are s 1  Forms +1 ions

 Very reactive  Don’t replace Hydrogen in Water ◦ Readily burn in O 2 when exposed to heat  Calcium makes up your bones.  Batteries get their name from this group  Have 2 Valence electrons ◦ All are s 2 – forms +2 ions

 These are the common metals  All have d orbitals filling  Less reactive than other metals  Copper, Silver, and Gold least reactive  Forms various positive ions

 Have 3 Valence electrons ◦ All are s 2 p 1 ◦ All form +3 ions except  Boron which forms a –3 ion  One is a metalloid (Boron)  The rest are all metals

 Carbon family has 4 valence electrons  All are s2 p2  Composed of: ◦ one non-metal (Carbon) ◦ Two metaloids (Silicon and Germanium ◦ Two metals (Tin and Lead)

 Carbon always forms 4 bonds ◦ All known life based on Carbon  Computers function based on Silicon and Germanium’s unique properties ◦ They conduct electricity but not heat  Lead and Tin are common metals ◦ Used to be used a lot in food storage

 All have 5 valence electrons ◦ All are s2 p3  Composed of: ◦ two nonmetals - Nitrogen and Phosphorous ◦ Two metalloids – Arsenic and Antimony ◦ One metal - Bismuth

 Nitrogen: ◦ makes up most of the atmosphere ◦ Critical to plant and animal life ◦ Forms strong bonds that are used in explosives  Phosphorous ◦ Critical to plant and animal life

 All have 6 valence electrons ◦ All are s2 p4 ◦ Usually form 2 bonds  Form – 2 ions (except Polonium +2, +4 ions)  Composed of: ◦ 3 nonmetals – Oxygen, Sulfur, Selenium ◦ 1 metalloid – Tellerium ◦ 1 metal - Polonium

 All have 7 valence electrons ◦ All are s2 p5 ◦ Forms 1 bond  Forms – 1 ions  All are nonmetals  Highly reactive ◦ Never found in nature as single atoms ◦ When pure will form F 2, Cl 2, Br 2, I 2

 All have 8 valence electrons ◦ All are s2 p6 ◦ Rarely form bonds  Never form ions ◦ Helium, Neon, Argon have never been found in a compound ◦ Krypton, Xenon, Radium can sometimes be forced to form compounds – but these are very unstable

 Called Rare Earths ◦ They are rare on earth - Most are manmade  All are radioactive  All elements greater then Uranium (92) are manmade  Some are used in medical research

 Left of Staircase  Ductile  Form positive ions  Lose electrons  Malleable  Conduct electricity and heat  Shiny

 Brittle  Dull  Do not conduct electricity  Do not conduct heat  Gain electrons  Form negative ions  Right of staircase

 Also called semimetals  Mix properties of both  Silicon conducts electricity (metal) but not heat (nonmetal).  Silicon is shiny (metal), but brittle (nonmetal)

 Elements in the same group will have similar chemical properties.  Elements in the same group have the same number and arrangement of valance electrons  Elements lose and gain electrons to achieve the Noble Gas configuration