Chapter 7: The Periodic Table of Elements

Ch 7 Section 1 Arranging the Elements

Vocabulary – Define on your own periodic Period Group Periodic law

Discovering a Pattern Dmitri Mendeleev Found pattern in 1869 Tried various properties: density, melting pt, etc But by arranging by atomic mass, he saw the pattern repeat Repeated every 7 elements

Discovering a Pattern Periodic  happens at regular interval Mendeleev realized there were missing elements based on the gaps

Changing the Arrangement Henry Moseley in 1914 Changed PTOE from atomic mass to atomic number

PTOE and Classes of Elements Metals Most common type of elements Left of the zig-zag line in PTOE Most are Solid Conduct electricity shiny

PTOE and Classes of Elements Non-metals Almost have a full set of electrons Usually a gas @ room temperature Metalloids Border the zig-zag region of PTOE Have properties of metal & non-metals

Decoding the PTOE Chemical Symbol See previous notes

Period Goes across the PTOE

Groups Vertical column

Ch 7 Section 2 Grouping the Elements

Group 1: Alkali Metals 4-5 facts

Group 2: Alkaline-Earth Metals 4-5 facts

Groups 3-12: Transition Metals 4-5 facts