# COPY.

## Presentation on theme: "COPY."— Presentation transcript:

COPY

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

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 8th 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 1st accepted PT: 1869
Elements ordered by ↑ atomic mass into columns with similar properties Predicted 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 Law There is a periodic repetition of chemical and physical properties of elements when arranged by increasing atomic number

Glenn Seaborg: 1950’s Lanthanide and Actinide Series

Newlands Seaborg Mendeleev Mosley

Vocabulary of PT Columns called groups or families
COPY Columns called groups or families Today: #1 thru 18, Arabic numerals Past: A & B groups, Roman numerals A-Group Columns 1,2,13-18 (= representative elements) IA – 8A B-Group Transition metals (columns 3-12) IB - 8B Rows are called series or periods #1 thru 7

Column numbering (1  18) left to right
Period numbering (1  7) top to bottom

Structure of Periodic Table
Closely related to electron configuration of each element COPY

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

Going Across Row 2: 2-8 Ne 18 (VIIIA) 2-7 F 17 (VIIA) 2-6 O 16 (VIA)
COPY 2-8 Ne 18 (VIIIA) 2-7 F 17 (VIIA) 2-6 O 16 (VIA) 2-5 N 15 (VA) 2-4 C 14 (IVA) 2-3 B 13 (IIIA) 2-2 Be 2 (IIA) 2-1 Li 1 (IA) Configuration Element Family

Going Down Column 1: 2-8-18-32-18-8-1 Fr 7 2-8-18-18-8-1 Cs 6
COPY Fr 7 Cs 6 Rb 5 K 4 2-8-1 Na 3 2-1 Li 2 1 H Configuration Element Period

Number of Valence Electrons
COPY 4 14 or IVA 3 13 or IIIA 2 2 or IIA 1 1 or IA Number of Valence Electrons Group

Valence Electrons Chemical behavior determined by # valence electrons
Elements with same # valence electrons will have similar chemical properties Elements in same column have similar chemical properties COPY

Classifying the Elements
COPY 2/3 (75%) of elements are metals Remaining elements: non-metals & metalloids (semi-metals) Metalloids: some properties of metals & some properties of nonmetals Staircase: dividing line between metals & nonmetals elements to left are metals (except H) elements to right are non-metals

Properties of Metals Malleable – flattened into sheets
COPY Malleable – flattened into sheets Ductile – drawn into wires & tubes have Luster Good Conductors of heat & electricity Solid at room temperature (except Hg) Metals lose electrons & form positive ions “Metals are losers” Low ionization energy Low electronegativity

Properties of Nonmetals
COPY generally gases or solids (except Br2) solids are Brittle solids are Dull poor conductors of heat & electricity Nonmetals gain electrons & form negative ions “Nonmetals are winners” High ionization energy High electronegativity Properties: OPPOSITE of metals

Properties of Metalloids
COPY 7 metalloids: 5 on right of staircase: B,Si,As,Te,At 2 on left of staircase: Ge,Sb Each metalloid has some metallic and some nonmetallic properties Example:Si shiny like metal but brittle like nonmetal

Names of Families (AKA group A elements)
COPY Group 1 = Alkali Metals Group 2 = Alkaline Earth Metals Groups 3-12: Transition metals Group 13 = Boron family Group 14 = Carbon family Group 15 = Nitrogen family Group 16 = Oxygen family Group 17 = Halogens Group 18 = Noble Gases

Transition Metals Groups 3 through 12 AKA group B elements
COPY Groups 3 through 12 AKA group B elements Actinide & Lanthanide series inner transition elements put the COLOR in your life form brightly colored salts/solutions

Elements that are gases at STP
Diatomics: H2, N2, O2, F2, Cl2 Monatomics: noble gases He, Ne, Ar, Kr, Xe, Rn COPY

Two Elements: liquid at room temperature
Br2 (non-metal) and Hg (metal) COPY

All other elements are solids at room temperature

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