1. Bohr Models of Atoms

2. Bohr Models:
In 1913, Neils Bohr proposed a model of the atom that helped explain the movement of electrons around the nucleus. He suggested that electrons move around the atom in orbits/shells. Each shell contains a definite number of electrons. After each shell is fill, the next orbit is then filled.

3. Example Maximum number of electrons in each shell
1st shell: ___electrons max. 2nd shell: ___ electrons max. 3rd shell: ___electrons max.
4th shell: ___ electrons max.
P N

4. Vocabulary: Outermost shell of an atom= valence shell Electrons within valence shell= valence electrons
A full outer shell of electrons = Stable Octet

5. Models REPRESENT Reality
Note: circles designate energy levels (electrons are not actually located in circles around the nucleus we represent them this way)

6. Fluorine
Atomic #: Atomic mass: p = n = e =
P N

7. Give these atoms a try: Nitrogen Phosporous
Atomic #: Atomic #:
Atomic mass: Atomic mass:
p = p =
n = n =
e = e =

8. Give these ions a try: Atomic #: Atomic #: Atomic mass: Atomic mass:
p = p =
n = n =
e = e =