PERIODIC TABLE Where it all is

What do you know? What stuff do you already know about the periodic table?

Mendelev’s Table Mendeleev’s table as published in 1869, with many gaps and uncertainties http://www.youtube.com/watch?v=0RRVV4Dio mg

How is it Arranged Based on increasing atomic number and on electron configurations Repeating chemical and physical properties. Groups or Families Columns that go up and down. Periods Rows that go across

Classification of Elements 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.

Group 1 – Alkali Metals Highly reactive All have 1 valence electron Forms +1 ions

Group 2 – Alkaline Metals Very reactive Have 2 Valence electrons All are s2 – forms +2 ions

Transitional Metals Groups 3 to 12 These are the common metals. D orbital metals. Forms various positive ions. You will be told their oxidation state.

Boron Family – Group 13 Have 3 Valence electrons Boron which forms a –3 ion One is a metalloid (Boron) The post transition metals form various cations

Carbon Family – Group 14 Carbon family has 4 valence electrons Carbon and silicon form a -4 charge Composed of: one non-metal (Carbon) Two metaloids (Silicon and Germanium

Group 15 – Nitrogen Family All have 5 valence electrons Nitrogen, phosphorus and arsenic form a -3 charge. Composed of: two nonmetals - Nitrogen and Phosphorous Two metalloids – Arsenic and Antimony

Group 16 – Oxygen Family All have 6 valence electrons Composed of: Oxygen, sulfur, selenium, and tellurium form -2 charges Composed of: 3 nonmetals – Oxygen, Sulfur, Selenium 1 metalloid – Tellurium

Group 17 - Halogens All have 7 valence electrons (all form a -1 charge) All are nonmetals Highly reactive Never found in nature as single atoms When pure will form F2, Cl2, Br2, I2

Group 18 – Noble Gases All have 8 valence electrons Rarely form bonds Never form ions Helium, Neon, Argon have never been found in a natural compound

Actiticides and Lanthicides 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

TRENDS Atomic Radius – The size of the atom. Smaller Up and Right Negative Ions Larger Positive Ions Smaller Ionization Energy – The energy required to remove electrons Greater Up and Right Fluorine the highest Francium the lowest

More on Trends 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.

Summarize what you learned What are the major trends of the periodic table? What are groups? What are periods? Summarize in your own words.