Transcript Introduction to Atomic Models:

Introduction to Atomic Models:
Diagramming the Atom
http://education.jlab.org/qa/atom_model_04.gif
Advantages of the Atomic Diagram:
• 2 Dimensional – can easily show on a
piece of paper
• Electron energy levels can be shown with
rings – closer to nucleus means lower
energy electrons
• Conventionally (traditionally) used – so
understood worldwide
• Easily identifies an atom by clearly
showing protons, neutrons & electrons
Truth:
Electrons
move around
in space, but
not along a
specific path!
Disadvantages of the Atomic Diagram:
• Not 3 Dimensional – can’t easily
understand the space used
• Rings for electrons can lead to the
misconception that electrons have
an orbital path
• Nucleus appears to take up more
space than it actually does Truth:
Nucleus is
less than 1% of
total volume of an
atom!
Guidelines for Diagramming Atoms:
1. Before beginning:
Determine the
number of
protons,
neutrons, and
electrons that are
found in that
atom.
http://lifesciencereality.files.wordpress.com/2008/06/atom.jpg
2. “Rules” about electron energy levels:
a. Lowest electron energy level is closest to
the nucleus.
b. Electron energy level increases moving
away from the nucleus.
c. Electron energy levels can only hold a
certain number of electrons.
d. Sometimes, electron energy levels can
overlap.
e. Electron energy levels fill up starting with
the lowest energy level first.