The Bohr Model of the
Atom
Topic #6
EQ
How can you identify an element
based on the number of electrons
and valence electrons?
What do we know?
Atoms have 2 main parts
Electron cloud -- contains electrons
Nucleus – contains protons and neutrons
Electrons = eProtons = p+
Neutrons = n0

What do you need to know?
There are 7 possible orbitals
 You can determine how many orbitals your
model has by looking at what period (row)
the element is on
 The orbitals hold a specific number of
electrons (which is the same as the atomic
number)

How many electrons per orbital?
Period 1 
orbital (ring) 1: 2 e-
Period 2 
orbital (ring) 1: 2 eorbital (ring) 2: 8 e-
Period 3 
orbital (ring) 1: 2 eorbital (ring) 2: 8 eorbital (ring) 3: 8 e-
Period 4 
orbital (ring) 1: 2 eorbital (ring) 2: 8 eorbital (ring) 3: 18 eorbital (ring) 4: 8 e-
Information to create a Bohr model






Element name and symbol:
Magnesium (Mg)
Atomic number: 12
Mass number: 24
Protons: 12
Electrons: 12
Neutrons: (24 - 12) = 12
Bohr model for Mg
12p+
12n
Bohr model for Al
13p+
14n0
Draw the following Bohr models
and Lewis Dot Structures
Boron
Carbon
Nitrogen
Oxygen
Fluorine
Aluminum
Silicon
Phosphorus
Sulfur
Chlorine