Download Atomic Theory - Aurora City Schools

Atoms’ families
• Remember that columns are groups or
families
• They have similar properties (e.g
reactivity, density, etc.) because
they have the same arrangement of
valence electrons
• Three big groups… metals, nonmetals
and metalloids (semiconductors)
Metals
• To the left of the stair-step
• Tend to give away electrons and
form positive ions
• Good conductors of heat and
electricity
• Can be stretched (ductile) and shaped
(malleable)
• Most are solids (1 liquid)
• U stream: Physical Science Series:
Atomic Structure and the Periodic
Table
Nonmetals
• To the right of the stair step line
• Tend to gain electrons and form
negative ions
• Poor conductors of heat and
electricity (good insulators)
• Are brittle…can’t be shaped
• Mix of solids and gases (1 liquid)
• U stream: Physical Science Series:
Atomic Structure and the Periodic
Table
Metalloids
• Between the other two on table,
touch the stair-step line
• Also called semiconductors
• Mixture of properties
• U stream: Physical Science Series: Atomic
Structure and the Periodic Table
Families have names, too
• Group 1: Alkali metals
– Soft, shiny
– React violently with water
– http://www.youtube.com/watch?v=QSZ-3wScePM
– Braniac
http://www.youtube.com/watch?v=m55kgyApY
rY
– 1 valence electron (+1 ion)
• Group 2: Alkaline Earth Metals
– Less reactive than alkali metals
– 2 valence electrons (+2 ion)
– http://www.youtube.com/watch?v=8GOPQVsbiGk
• Transition metals
– Groups 3 – 12
– Have multiple ions (+1, +2, +3, +4)
Families have names, too
• Group 17: Halogens
– Very reactive
– 7 valence electrons (-1 ion)
– http://www.youtube.com/watch?v=u2ogMUDBa
f4
• Group 18: Noble gases
– Don’t react at all
– No charge! Outer energy level is full.
– Exist as single atoms, e.g. Ar or He (others exist
as compounds, because they react with their
elements, e.g. O2)