Periodic Table of Elements

Dmitri Mendeleev
arranged the known 60 elements by increasing atomic mass

Modern Periodic Table
arranged by increasing atomic number
118 elements

Block on Table

• element name
• symbol
• atomic number
• average atomic mass
• state of matter

Group

• column on table
• also called family
• elements in the same group have similar chem. prop.
• react w/ other elements in similar manner

Period

• row on table
• atomic # increases by one as you move across
• prop. repeat in the same pattern from rt. to left across ea. period

Metals

• shiny
• ductile
• malleable
• conductivity
• reactivity

Untitled Slide

• left of zigzag line
• reactivity decreases
• left to right
• lose valence electrons
• solids

Groups

• alkali metals (1)
• alkaline earth (2)
• highly reactive
• never found alone

More Stable Groups

• transition metals (3-12)
• mixed groups

Rare Earth Metals

• bottom of table
• lanthanides
• actinides

Synthetic Elements

• greater than 92
• particle accelerator

Nonmetals

• lack prop. of metals
• solids: dull, brittle
• most are gases
• poor conductivity
• reactivity

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• right of zigzag line
• reactivity increases
• right to left from 17
• gain or share
• valence electrons

Mixed Groups

• carbon (14)- life
• nitrogen (15) - air
• oxygen (16) - air/h2o

Halogens (17)

• most reactive
• salt forming
• fluorine combines 
• with most anything

Noble Gases (18)

• unreactive
• valence electrons
• full valence energy level

Hydrogen

Metalloids

• varying conductivity
• solids
• along zigzag line
• mix of met. & nonmet.