Periodic Table
Study Guide
How to
Draw Bohr
Diagrams
Bohr Diagrams
1)
2)
3)
Find your element on the periodic table.
Determine the number of electrons – it is the same
as the atomic number.
This is how many electrons you will draw for a
neutral atom.
Bohr Diagrams
•
•
•
Find out which period
(row) your element is in.
Elements in the 1st period
have one energy level.
Elements in the 2nd period
have two energy levels,
and so on.
Bohr Diagrams
1)
2)
Carbon is in the 2nd
period, so it has two
energy levels, or
shells.
Draw the shells around
the nucleus.
Bohr Diagrams
1)
2)
3)
Add the electrons.
Carbon has 6
electrons.
The first shell can only
hold 2 electrons.
Bohr Diagrams
1)
2)
3)
Since you have 2
electrons already
drawn, you need to
add 4 more.
These go in the 2nd
shell.
Add one at a time starting on the right
side and going
counter clock-wise.
Bohr Diagrams
1)
2)
3)
4)
5)
Check your work.
You should have 6
total electrons for
Carbon.
Only two electrons
can fit in the 1st shell.
The 2nd shell can hold
up to 8 electrons.
The 3rd shell can hold
18, but the elements in
the first few periods
only use 8 electrons.
Bohr Diagrams
+ + ++
+ +
1)
or
2)
6p 6n
3)
As you get proficient in
drawing the Bohr model,
add the number of
protons and neutrons to
the nucleus.
You should have 6 total
protons for Carbon-12
and 6 neutrons.
Remember that the
Atomic Mass is the
average total of protons
and neutrons in the
nucleus.
Bohr Diagrams
Try the following elements
on your own:
a)
b)
C
6p 6n
c)
d)
e)
f)
H
He
O
Al
Ne
K
Bohr Diagrams
Try the following elements
on your own:
a)
b)
H
1P
c)
d)
e)
f)
H – 1 electron
He
O
Al
Ne
K
Bohr Diagrams
Try the following elements
on your own:
a)
b)
He
2P 2N
c)
d)
e)
f)
H
He - 2 electrons
O
Al
Ne
K
Bohr Diagrams
Try the following elements
on your own:
a)
b)
O
8P 8N
c)
d)
e)
f)
H
He
O - 8 electrons
Al
Ne
K
Bohr Diagrams
Try the following elements
on your own:
a)
b)
Al
13P 14N
c)
d)
e)
f)
H
He
O
Al - 13 electrons
Ne
K
Bohr Diagrams
Try the following elements
on your own:
a)
b)
Ne
10P 10N
c)
d)
e)
f)
H
He
O
Al
Ne - 10 electrons
K
Bohr Diagrams
Try the following
elements on your own:
a)
b)
K
19P 20N
c)
d)
e)
f)
H
He
O
Al
Ne
K - 19 electrons
Bohr Diagrams
End of Study Guide.
You should know how to
draw a Bohr Diagram
for the first 20 elements.