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X Unit 11 Notes: The Periodic Table

History of the Periodic Table

  1. Antoine Lavoisier(1743-1794)
  • Published Elements of Chemistry in 1789 with included a list of “simple substances” (which we now know to be elements)
  • Formed the basis for the modern list of elements
  1. Johann Döbereiner(1780-1849)
  • Groups of three elements with related properties and weights
  • Began in 1817 when he realized strontium was halfway between the weights of calcium and barium and they all possessed similar traits
  • Dӧbereiner’s triads =
  1. John Newlands(1837-1898)
  • Stated that elements repeated their chemical properties every ______element
  • Similar to the idea of octaves in music
  1. Dmitri Mendeleev(1834-1907)
  • Arranged elements based on accepted ______and properties that he observed
  • Listed elements with similar characteristics in the same family/group
  1. Henry Moseley(1887-1915)
  • English physicist who arranged elements based on increasing ______
  • His periodic table looked similar to Mendeleev’s design since as atomic number increases, so does the atomic mass
  1. Glenn Seaborg (1912-1999)
  • American chemist credited with the synthesis of nine actinide elements
  • Won Nobel Prize for suggesting actinide elements fill an f sublevel
  • Element 106 named after him:

Periodic Law

  • Periodic –
  • Modern periodic law – When elements are arranged in order of increasing atomic number, there is a periodic repetition of their properties

Reading the Periodic Table

  • Periods –
  • Groups or Families –

•Metals - shiny, smooth, solid at room temperature, good conductors of heat and electricity, malleable and ductile.

•Metalloids (along stair step line) physical and chemical properties of both metals and nonmetals- B, Si, Ge, As, Sb, Te

•Nonmetals – low melting and boiling points, brittle, dull-looking solids, poor conductors of heat and electricity.

Periodic Table and Electronic Structure

  • Valence electrons are periodic!

Ex.) Write the noble gas configurations for:

  • F
  • Cl
  • Br
  • I

***______have similar valence electron configurations!

Groups of Elements

Group 1 = Alkali Metals

Group 2 = Alkaline Earth Metals

Group 17 = Halogens

Group 18 = Noble Gases

Transition Metals

Lanthanides and Actinides

Periodic Properties & Trends

Electronegativity –

***TREND: Increases going ______and to the ______.

Across a period 

Down a group 

Atomic Radius –

***TREND: Increases going ______and to the ______.

Down a group 

Across a period 

***Remember***LLLL  Lower, Left, Large, Loose

Ionization Energy –

  • 1st I.E. =
  • 2nd I.E. =
  • 3rd I.E. =

Ex. B --> B+ + e-I.E. = 801 kJ/mol

Ex. B+ --> B+2 + e-I.E.2 = 2427 kJ/mol

Ex. B+2 --> B+3 + e-I.E.3 = 3660 kJ/mol

***TREND: Increases going ______and to the ______.

Down a group 

Across a period 

Metallic Character –

***TREND: Increases going ______and to the ______.

Think about where the metals and nonmetals are located on the periodic table to help you remember the trend for metallic character!!

Ionic Radius –

•Ionic Radius of Cations

•Ionic Radius of Anions

***Cations are ______than the atoms from which they form.

***Anions are ______than the atoms from which they form.

OVERALL PERIODIC TRENDS

Property / Group Trend / Period Trend
Atomic Radius
Ionization Energy
Electronegativity
Metallic Character

Summary of Periodic Trends