Transcript DNA

Cornell Notes: Please take out
your notebook and properly set
up your paper.
Topic: Bohr Model
Date: 11/19/2012
Essential Questions:
What does an atom’s structure look
like?
How are electrons configured in atoms?


What are
subatomic
particles?
How do we
determine the
number of
Subatomic
Particles in an
atom?

The parts that make up an atom.
◦ PEN: Protons, Electron, Neutrons

Atomic Number= # of protons &
electrons (in a neutral atom)
Atomic Mass= #protons + # neutrons
Mass
#
Protons

What is the
Bohr Model?


1
1
Bohr’s Model was used to explain the
energy of atoms
Only works for Hydrogen, but is a
good visualization for atomic
structure
P+: 1
E-: 1
N0:1-1= 0
nucleus
1p+
e
Electron
Energy Shell
+
-

How do we
make a Bohr
Model?
1.
2.
Determine # protons & Neutron
draw them in inner circle
Determine # Electrons place in
energy levels as follows
 1st energy level= 2e- max
 2nd energy level= 8e- max
 3rd energy level= 18e- max
Nitrogen-14
1. Determine # protons &
Neutron draw them in inner
circle
2. Determine # Electrons place
in energy levels as follows
1st energy level= 2e- max
2nd energy level= 8e- max
3rd energy level= 18e- max
P+
EN0


What are
Valence
Electrons?
What’s the
Octet Rule?

Electrons in the outer most shell
◦ Determine elements chemical properties

Atoms gain, lose, or share
electrons in order to have 8 valence
electrons
How do valence electrons affect an
element’s reactivity?