TOIPC: Periodic Table Organization Do Now: From your activity yesterday, and p.5 answer page 6 in your packet

Periodic Law increasing atomic numberThere is a periodic repetition of chemical and physical properties of elements when arranged by increasing atomic number

What is the periodic table? compact way of organizing elements contains a lot of information allows us to make predictions about behaviour and properties of elements Elements

The periodic table hasn’t always look like this

History of the Periodic Table End of the 1700’s – less than 30 elements known Many elements discovered during 1800’s Many experiments done to determine atomic masses

John Newlands 1864: if elements arranged by atomic mass - properties repeat every 8 th element Law of Octaves –did not work for all known elements Key idea was correct: Properties of elements do repeat in periodic way

Mendeleev & Meyer Mendeleev produced 1 st accepted PT: 1869 Elements ordered by ↑ atomic mass into columns with similar properties PredictedPredicted existence & properties of undiscovered elements Not totally correct –more accurate atomic mass calculations showed some elements weren’t in right place

Remember 1860’s: No subatomic particles yet discovered Dalton’s billiard ball model of the atom

1913 – Henry Moseley by 1913, protons & electrons discovered –Neutrons were predicted Moseley determined atoms of each element contain unique # protons (= atomic number) rearranged Mendeleev’s PT by atomic number instead of mass problems with elements in wrong place disappeared

Periodic Table is arranged according atomic number and organized into groups and periods

COLUMNS Groups/Family numbering (1  18) left to right TELL US NUMBER OF VALENCE ELECTRONS (KIND OF)

Valence Electrons – electrons in the outer shell Chemical behaviour determined by # valence electrons Elements with same # valence electrons will have similar chemical properties –Elements in same column have similar chemical properties

Going Down Column 1: Fr Cs Rb K Na3 2-1Li2 1H1 ConfigurationElementPeriod

Valence Electrons 414 or IVA 313 or IIIA 22 or IIA 11 or IA Number of Valence Electrons Group

COLUMNS groupsfamiliesAka groups or families –#1 thru 18, Arabic numerals –(old way, Roman Numerals and letters) –- tell us number of valance electrons (KIND OF) = works for 1,2, 13,14,15,16,17,18 COLUMNCOLUMN Turn to packet page one, lets label the columns and valence electrons

Names of Families (AKA group A elements) Group 1 = Alkali Metals Group 2 = Alkaline Earth Metals Groups 3-12: Transition metals Group 17 = Halogens Group 18 = Noble Gases

Transition Metals (in yellow) Groups 3 through 12

form brightly colored salts

Glenn Seaborg: 1950’s f-Block Metals Lanthanide (rare Earth metals) – can be found naturally on Earth, only 1 is radioactive Actinide– all are radioactive, some are made in the lab. INCLUDES Uranium Turn to packet page one, lets label the the f-block metals

ROWS Period numbering (1  7) top to bottom TELL US NUMBER OF SHELLS (energy levels)

Energy Levels = Row Number Elements in same row have same # of principal energy levels

ROWS seriesperiodsRows are called series or periods –#1 thru 7 - TELL US HOW MANY ENERGY LEVELS ROW Turn to packet page one, lets label the periods