Transcript metals - Cloudfront.net

Elements and Their Properties
Section 1 Metals
Think about what you are wearing. List all of
the metal objects that are on your body right
now…
Objectives
• The properties of metals
• Identify alkali metals and alkaline earth
metals
• The difference among transition elements.
Properties of Metals
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Good conductors of heat & electricity
Solid at room temperature (exception Hg)
Lustrous (reflect light)
Malleable (hammered/rolled into thin sheets)
Ductile (can be drawn through wires)
Ionic Bonding in Metals
• Tend to have 1, 2, or 3 valence electrons
• In chemical reactions, metals tend to give up
electrons easily.
• When metals react with nonmetals, metals tend to
lose electrons to nonmetals = both are more
stable as ions
• Ion- def. charged particle that has either more or
fewer # of electrons than the # of protons
Metallic Bonding
• Occurs bc e- move freely among a metal’s + charged
ions e- form a cloud around the metal ion
• RESULT: ductility & ability to conduct electricity
• Ex: metal hammered into sheets doesn‘t break bc ions
are in layers that slide past each other w/out losing
their attraction to the
electron cloud
• Ex: good conductor of
electricity bc
outer-level electrons
are held weakly
Alkali Metals
• Group 1A -1 electron in outer shell
(gives it up and becomes +1 ion)
• Soft enough to cut with a knife
• Most reactive of all metals 
therefore don’t occur in nature in pure
elemental form
• Form stable compounds with
nonmetals
• All react vigorously with water and
oxygen
• Stored in substances that are not
reactive (ex: oil)
The Alkaline Earth Metals
• Group 2A -2 electrons in outer shell
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(gives them up and becomes +2 ion)
Exceptionally light, yet strong
added to alloys
Combine easily with oxygen
forming minerals that are found in
the Earth’s crust
Be- used as alloy to make tools that
don’t spark when strike surface
used in places where preventing
fires is crucial (oil refineries)
Mg- produces brilliant white flame;
used in cars, planes, and space
crafts bc lightness and strength;
ladders, bats; in chlorophyll which is
allows plants to make food
• Ca- shiny metal, but
seldom seen bc
easily joins with other
elements
• Strong compounds
make great
construction
materials statues
and some
countertops
• helps make bones
and teeth strong
body contains 2.2 lbs
of Ca
• Sr- when exposed to
air silvery metal
reacts with oxygen and
quickly turns yellowish
• Burns bright red
used in fireworks and
signal flares
• Ba- swallow BaSO4 to
test for digestive
disorders (absorbs xray radiation)
• Ra- radioactive element
that was once used in
paint, toothpaste etc
until people began to
die from radiationrelated illnesses
Transition Elements
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Groups 3-12
Dense, hard, strong metals with high melting points
Conduct electricity, resist corrosion, easily mixed to make alloys
Occur in nature as uncombined elements More stable than
group 1 and 2
• Often form colored compounds
• Ex: paint pigments, fireworks
Iron, Cobalt, and Nickel
• Iron triad
• Used to create steel and
other metal mixtures
• Fe- can be molded into
almost any shape main
component of steel and most
widely used metal; 2nd most
abundant metallic element in
Earth’s crust (after Al)
• Ni- added to give
strength or shiny
protective covering
doesn’t tarnish in air
Copper, Silver, and Gold
• Group 11
• So stable and malleable
• Can be found as free
elements in nature
• Au- rare, precious metal
that is unchanged by air,
water, or time
• Ag- best conductor
used in high quality
electrical wires, germs
are unable to grow on
silver ideal for medical
equipment
• Cu- electrical wiring, less
expensive
Group 12
• Hg- silvery, liquid metal;
thermometers until
found out poisonous
• Amalgam is a safe alloy
of mercury used to fill
cavities in teeth
• Zn & Cd used to coat
other metals
• Cd- rechargeable
batteries
The Inner Transition Metals
Lanthanides follow Lanthanum
•Europium, gadolinium, and terbium are used to
produce the colors on a TV screen
Actinides follow Actinium
•All radioactive and unstable
•Thorium & Uranium found in Earth’s crust
•Th- used to make highquality glass for camera lens
•U- use in nuclear reactors and weapons
Poor Metals [Magnificent Seven]
• Softer and lower melting
points than transition
metals
• Include some of the
most useful elements on
Earth
• In- used in touch screen
devices bc soft enough
to dent with your
fingernail
• Al- light, doesn‘t rust,
combines with oxygen
to form weatherproof
coating
• Pb- roofing material,
dissolved lead is
poisonous
HOMEWORK
• Foldable- include periodic
table cutout, properties,
and examples
Alkali
Metals
METALS
Alkaline
Earth Metals
Transition
Metals