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Section 4.4 The Periodic Table. History. 1790s, French scientist Lavoisier 23 elements 1800s: electricity and spectrometer. John Newlands. Patterns on the periodic table Law of octaves Elements on the eights had similarities. Meyer & Mendeleev.
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History • 1790s, French scientist Lavoisier • 23 elements • 1800s: electricity and spectrometer
John Newlands • Patterns on the periodic table • Law of octaves • Elements on the eights had similarities
Meyer & Mendeleev • 1869: connection between atomic mass and properties • Mendeleev published first • Left holes of undiscovered elements
Moseley • Problems with Mendeleev • Rows by increasing atomic mass • Moseley used atomic number instead
The Periodic Law • There is periodic repetition of chemical and physical properties when elements are arranged by increasing atomic number.
The Modern Periodic Table • Horizontal rows- periods (7) • Vertical columns- groups or families (18)
Groups 1,2 and 13-18= Representative Elements • Groups 3-12= Transition Elements
Metals • shiny, smooth • solid room temperature • good conductors of heat and electricity
Alkali Metals • Group1 (excluding hydrogen) • highly reactive
Alkaline Earth Metals • Group 2 • highly reactive (not as much as 1)
Group B Metals • Transition metals • elements contained in D block • Inner transition metals • the lanthanide (4f) and actinide (5f) series
Nonmetals • Generally a gas or a brittle, dull solids • Poor conductors
Nonmetal Families • Halogens= group17 • REALLY REACTIVE • Noble Gases= group18 • Unreactive/stable (all valence electrons are filled)
Metalloids • Have characteristics of both metals and nonmetals • B, Si, Ge, As, Sb, Te, At • Separate metals on the left from nonmetals on the right