Download Elements!

Elements!
Elements
►A
pure element is
made of many of the
same atoms.
►
Common elementsAluminum, Oxygen, Carbon
(about 100 others)
► Elements
cannot
normally be broken
apart into smaller
substances
Demitri Mendeleev-
Russian chemist who
developed the first periodic
table in 1869.
The periodic table organizes
elements by common
http://www.germes-online.com/direct/dbimage/50327532/Aluminum_Alloy_Pipe.jpg
characteristics!
http://serc.carleton.edu/images/usingdata/nasaimages/peri
odic-table.gif
http://www.jinshanmines.com/i/photos/Jinshan_GoldBar.jpg
Atomic Model and Subatomic
Particles
Subatomic particles
• Atomic Model
has changed
dramatically
through
history
•Subatomic
particles make
up all atoms
Protons
Found in the nucleus
(center of atom)
 The electric charge is
positive (+)
 Weighs 1 amu
(atomic mass unit)
 Each element has a unique
number of protons
(All Oxygen atoms have 8
protons; all Iron have 26)

Atoms are
identified by
their number
of protons.
Neutrons




Also makes up
part of nucleus
No electric
charge
Weighs 1 amu
Number of
neutrons in the
nucleus can
change (Isotopes)
Electrons




Found surrounding the
nucleus in energy
levels
Negatively (–) charged
particle
Weighs 1/2000 amu
At one time thought to
be nuclear garbage.
Now, the most
important part
of chemistry

VIP of Chemistry
Electron Energy
Levels
• Electrons have energy
(they have motion)
• Electrons surround
nucleus in energy
levels
• Electrons fill the lowest
energy level first which
is closest to the
nucleus