Download Atomic Structure Notes

ATOMIC
STRUCTURE
NOTES
ESSENTIAL QUESTION:
EXPLAIN WHAT AN ATOM IS. WHAT ARE THE
SUBATOMIC PARTICLES OF AN ATOM? WHAT ARE
THEIR CHARGES, LOCATIONS, AND MASS?
MATTER
•Anything that has mass and
takes up space
•Elements are made of matter
ATOMS
• Smallest unit of an element (pure substance, the same
throughout)
• Within the atom is:
• Nucleus: in the center, containing most of the mass
• Electron Cloud: surrounding the nucleus, much more
space and almost no mass.
NUCLEUS VS.
ELECTRON CLOUD
NUCLEUS
ELECTRON CLOUD
•Protons
•Electrons
•Neutrons
•Valence
Electrons
PROTONS
•Location:
Nucleus
•Charge: Positive
•Mass: 1 amu
• It’s the Atomic Number
on the Periodic Table
• Gives the element it’s
identify (like a
fingerprint, no other
element has the same
amount of protons).
NEUTRONS
•Location:
Nucleus
•Charge: No
Charge (Neutral)
•Mass: 1 amu
• To Find the number of
Neutrons:
• Take the Atomic
Mass and subtract
the Atomic Number
ELECTRONS
•Location:
Electron Cloud
•Charge: Negative
•Mass: 0.001 amu
• Electrons = Protons (in
neutral atoms)
• There are different energy
levels in the cloud
• 1st energy level: holds up to
2 electrons
• 2nd and 3rd energy levels:
both hold up to 8 electrons
VALENCE ELECTRONS
• Location: Electron
Cloud, Last Energy
Level only
• Charge: Negative
• Mass: 0.001 amu
•Tells you the
reactivity &
chemical properties
of the element
•Puts the elements
into groups
PERIODIC TABLE
14
Si
28.086
Silicon
Atomic Number =
Protons = Electrons
Element
Symbol
Atomic Mass
(Mass Number)
Element Name
APE MAN
•APE  Atomic # =
Protons = Electrons
•MAN  Mass # Atomic # = Neutrons