Where it all is

 John Newlands determined a repeating pattern of every 8 elements. He called it the law of octaves.  Developed in the 1860’s  Dmitri Mendeleev arranged the first on based on Atomic Masses.  Henry Moseley Arranged the Modern Periodic Table based on Atomic Number.

 Based on increasing atomic number and on electron configurations ◦ Results in repeating chemical and physical properties.  Groups or Families ◦ Columns that go up and down. ◦ There are 18 Groups  Periods ◦ Rows that go across ◦ There are 7 Periods

Metals ◦ On the left side ◦ Make up ¾ of all elements ◦ Malleable, Ductile, Conduct electricity, form positive ions.  NonMetals ◦ On the Right side ◦ Dull, Brittle, Insulators, form negative ions  Metalloids (Semimetals) ◦ Found along the staircase between metals and nonmetals, have properties of both.

 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 then 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

 Atomic Radius – The size of the atom. ◦ Hard to measure due to cloud not being distinct ◦ Smaller Up and Right ◦ Negative Ions Larger ◦ Positive Ions Smaller  Ionization Energy – The energy required to remove one electron, the more electrons removed, the more energy required. ◦ Greater Up and Right ◦ Fluorine the highest ◦ Francium the lowest

 Electronegativity – The ability of atoms to attract electrons during bonding ◦ Greater Up and Right ◦ Fluorine the Greatest Electronegivity ◦ Francium the Lowest  Octet Rule – Atoms Tend to gain, lose or share electrons to have a full (s2, p6) valence shell.  Shielding Effect – The ability of inner electrons to shield valence electrons from the nucleus. Increase Down, Across Same