2. How do we know how many electrons
are in an atom??
• From the ATOMIC NUMBER!
Atomic # # of protons # of protons = # of
electrons
3. Da Rules:
• Electrons are found in
the________________.
Electron Cloud
• The electrons fill into
Energy Levels
_________________ or
Rings
__________________.
• They electrons always
inside
fill from the _________
outside
to the ____________.
4. Da Rules
• The first energy level
can contain _______
2
electrons.
• The second and third
energy level can
8
contain _______
electrons.