Transcript Atoms and the Periodic Table

The Periodic Table
 Dimitri
Mendeleev was the Russian
scientist who developed the modern
Periodic Table
 The Periodic Table is an arrangement of all
elements in order of atomic number.
Groups (family)
A
column in the periodic table
 Elements have similar properties
 Elements have the same number of
valence electrons (Outer Ring
Electrons)
Periods
A
row on the periodic table
 Elements in the same period have the same
number of electron rings
Properties of Elements
An
element’s physical and chemical
properties can be predicted by its
location on the periodic table.
Hydrogen



Composed of a single proton and a single electron, hydrogen
is the simplest and most abundant element in the universe
It is estimated that 90% of the visible universe is composed of
hydrogen.
Hydrogen is the raw fuel that most stars 'burn' to produce
energy.
Metals
 Located
on the left side of the zig-zag line
 Lose electrons easily during chemical reactions
 Solid at room temp. (except for mercury – Hg)
 Good conductors of heat & electricity
 Shiny
 Malleable: Can be hammered into sheets
 Ductile: Can be pulled into wire
Alkali Metals
 Group
1 on periodic table
 Lustrous, silvery solids
 Soft enough to be cut with a knife
 Highly reactive (not found as free metal in
nature)
 Get more reactive as you move down the
group
 Sodium and Potassium are essential to life for
animals and plants
Alkaline earth metals
 Group
2 metals
 Denser, harder and have higher melting and
boiling points than group 1 metals
 Less reactive than group 1, but still highly
reactive (not found in nature as free metals)
 Magnesium used to harden aluminum and as
antacid (help settle upset stomach)
 Calcium needed by living things
http://www.chem4kids.com/files/elem_transmetal.html
Transition Metals
 Most
of the metals are transition metals
 Include most of the common metals like iron,
nickel, silver, zinc, gold, copper, etc.
 Hard and shiny
 Good conductors of electricity
 Stable – react slowly or not at all with air and
water
 Some transition metals used by living things
Uses for Transition Metals
–electric wires, pots, pennies
 Iron –building construction, steel
 Mercury (Hg)– used in some thermometers
(poisonous liquid metal)
 Silver – jewelry, photography, medicine, coins
 Tungsten (W) – light bulb filaments
 Zinc – prevents rust, used in dry cell batteries
 Copper
Mixed group metals
Good electrical conductor
 Is mixed with other metals to make a strong alloy for
use in cars, planes and furniture

Mixed group metals

Used as a coating for steel on food storage
cans to protect it from corrosion
Mixed group
metals
Was used in paint and water pipes –
not today
 Poisonous
 Very heavy
 Used now in automobile batteries
 Used for weights (fishing, diving, etc.)

Nonmetals
 Located
on the right side of the zig-zag line
 Usually gain or share electrons during chemical
reactions
 Includes gases
 Dull, Brittle – if solid
 Not malleable or ductile
 Not good conductors
Nitrogen & Oxygen
 Nitrogen
– about 78% of Earth’s atmosphere
 Oxygen –
 nearly
21% of the earth's atmosphere
 nearly half of the mass of the earth's crust
 two thirds of the mass of the human body
 highly reactive element and is capable of combining
with most other elements
 required by most living organisms
 required for most forms of combustion
Carbon

Many carbon compounds are essential for life as we know
it (entire branch of chemistry – organic chemistry devoted to carbon compounds)

Graphite - one of the softest materials known, used in
pencils and as a lubricant

Diamond – one of the hardest materials known, a girl’s
best friend!!, also used on saw blades
Noble Gases
Very stable and non-reactive (inert)
 Do not usually form compounds with other elements
 Neon - used in advertising signs.
 Argon - used in light bulbs
 Helium - used to cool things and in balloons


2nd most abundant element in the universe
Xenon - used in headlights for new cars
 When you move down the periodic table, these
elements become more rare.

Halogen Family
Halogen means “salt-forming”
 Very reactive – like to bond with group 1 elements
 Iodine very important for your body – heart, blood
and bones, also used to kill germs on wounds
 Fluorine – most reactive of all the elements - helps
prevent tooth decay

Other Important Non-Metals
 Phosphorus
compounds are used in:
 Soft
drinks
 Fertilizers for plants
 Baking powder
 Sulfur
compounds are used in:
 Fertilizer
for plants
 Medicines – antibiotics (kill bacterial infections)
 Insecticide – kills bugs
 Disinfectant – kills germs
Metalloids
Germanium & Silicon
Have properties of metals and
nonmetals
 Touch the zig-zag line
 Germanium & Silicon are used
in computer chips, transistors
and lasers
 Silicon is the 2nd most
abundant element in Earth’s
crust

Metalloids
Boron



Used in cleaning solutions,
cosmetics and medicine
Used in producing fiberglass
Also an important ingredient in
agricultural chemicals and fire
retardants
Challenge
Use your notes and the websites listed to answer the
challenge on the back of your paper.