Transcript 20161028074577x

Representative
Groups (Families)
Chapter 5 Section 3
Pg. 139-149
• Why is Hydrogen on the left side of the
periodic table with the active metals?
– It is a nonmetal gas that seems to have more in
common with the nonmetals in Group 17
• Hydrogen’s location is related to its electron
configuration, not its properties
• Group 1
– Have single valence electron and are extremely
reactive
– Found in nature only in compounds because they
are so reactive
• The reactivity of alkali metals increases from
the top of Group 1 to the bottom
• Sodium and potassium are stored under oil to
keep them from reacting with the oxygen and
water vapor in air
• Group 2
– All have 2 valence electrons
– Harder metals than metals in group 1
• Differences in reactivity among the alkaline
earth metals are shown by the ways they
react with water
• Magnesium
– Plays a key role in the process that uses sunlight to
produce sugar in plants
– The center of chlorophyll is magnesium
– A mixture of magnesium and other metals can be
as strong as steel, but much lighter
• Calcium
– Body needs calcium to keep
bones and teeth strong
– Calcium carbonate: compound of calcium, carbon,
and oxygen- main ingredient in chalk, limestone,
coral, and
pearls
• Group 3
– All have 3 valence electrons
• Aluminum is the most abundant metal in
Earth’s crust
• Group 4
– 1 nonmetal (carbon), 2 metalloids (silicon,
germanium) and 2 metals (tin, lead)
– Each has 4 valence electrons
• Except for water, most of the compounds in
your body contain carbon
• Silicon is the second most abundant element
in Earth’s crust
• Group 5
– Has 2 nonmetals (N, P), 2 metalloids (As, Sb), and
1 metal (Bi)
– Wide range of physical properties
– All have 5 valence electrons
– Nitrogen: nonmetal gas
– Phosphorus: solid nonmetal
– Bismuth: a dense metal
• Besides nitrogen, fertilizers often contain
phosphorus
• Group 6
– All have 6 valence electrons
• Oxygen is the most abundant element in
Earth’s crust
– Complex forms of life need oxygen to stay alive
because it releases the energy stored in food
– Ozone is another form of oxygen; at ground level
it is an irritant, at upper levels it absorbs harmful
radiation emitted by the sun
• Sulfur was one of the first elements to be
discovered- found in large natural deposits
• Group 7
– Each has 7 valence electrons
• Despite their physical differences, the
halogens have similar chemical properties
– Highly reactive nonmetals (fluorine most reactive,
chlorine is a close second)
– React easily with most metals
• Group 8
– Each has 8 valence electrons with the exception of
Helium which has 2
– Colorless and odorless and extremely unreactive
• Some light bulbs are filled with argon because
the glowing filament in the bulbs will not react
with argon as it would react with oxygen