Transcript The Periodic Table Chapter 12 Grouping the Elements Section 2 Reminder… Groups AKA Families • Elements in each family have similar but not identical properties. – For.

The Periodic Table
Chapter 12
Grouping the Elements
Section 2
Reminder…
Groups
AKA Families
• Elements in each family have similar but not
identical properties.
– For example, lithium (Li), sodium (Na), potassium (K),
and other members of family IA are all soft, white,
shiny metals.
• All elements in a family have the same number of
valence electrons.
– valence electrons – an electron that is found in the
outermost shell of an atom and that determines and
atom’s chemical properties
Families of the
Periodic Table
Hydrogen
• sits on top of Group 1
– BUT it is not a member of that
family
– Hydrogen is in a class of its
own
• gas at room temperature
• 1 proton, 1 electron, & only 1
energy level
• needs 2 electrons to fill up its
valence shell
Alkali Metals
• Group 1
• have a single electron in their
outermost level, in other
words, 1 valence electron
• shiny
• have the consistency of clay
• easily cut with a knife
Alkali Metals
• most reactive metals
• react violently with water
• never found as free elements
in nature - are always
bonded with another
element
Alkaline Earth Metals
• Group 2
• never found uncombined in nature
• 2 valence electrons
Transition Metals
• Groups 3-12
• good conductors of heat
and electricity
• 1 or 2 valence electrons
Rare Earth Elements
• below the Periodic Table
• 30 rare earth elements are
composed of the
lanthanide and actinide
series
• types of transition metals
• lanthanide: shiny, reactive
metals
• actinide: man-made
metals
Boron Family
• Group 13
• named after the first element in
the family
• 3 valence electrons
• includes a metalloid (boron),
and the rest are metals.
• includes the most abundant
metal in the earth’s crust
(aluminum).
Carbon Family
• Group 14
• 4 valence electrons.
• includes a non-metal
(carbon), metalloids, and
metals
• carbon is called the “basis of
life”
Nitrogen Family
• Group 15
• 5 valence electrons
• named after the element that
makes up 78% of our
atmosphere
• includes non-metals,
metalloids, and metals.
Oxygen Family
• Group 16
• 6 valence electrons
• share electrons when
forming compounds
• oxygen is the most
abundant element in the
earth’s crust
Halogen Family
• Group 17
• 7 valence electrons
– which explains why they are
the most active non-metals
• need to gain 1 electron to fill
their outermost energy level
• never found free in nature
• react with alkali metals to
form salts
Noble Gases
• Group 18
• colorless gases that are extremely un-reactive
– inactive because their outermost energy level is full
• all the noble gases are found in small amounts
in the earth's atmosphere