Transcript Using the Bohr Model to Build an Atom

Using the Bohr Model to Build an
Atom
Remember what the periodic table
gives you…
# of p+ Atomic
=
Or
Number
# of e-
7
N
14.007
Atomic
= (# of n0) + (# of p+)
Mass
Chemical
Symbol
Number of Neutrons?
• You’ll need to do a little calculation…
• Remember that:
– Atomic number = p+
– Atomic mass = (p+) + (n0)
• So to calculate # of n0…
– [(p+) + (n0)] – (p+) = n0
– Atomic mass – Atomic Number = # of neutrons
Let’s Build an Atom…
=
p+
2
He
4.0026
= n0
= e-
Step 1: Build the Nucleus – insert protons.
Step 2: Build the Nucleus – insert neutrons.
Step 3: Construct the first orbital and fill it with up to 2 electrons.
Let’s Build a Bigger Atom…
5
B
10.811
Step 1: Build the Nucleus – insert protons.
Step 2: Build the Nucleus – insert neutrons.
Step 3: Construct the first orbital and fill it with up to 2 electrons.
Step 4: Construct the second orbital and fill it with up to 8 electrons.
How Can We Do This On Paper?
15
P
30.974
15p+
16n0
2e- 8e- 5e-
Step 1: Build the Nucleus – insert protons.
Step 2: Build the Nucleus – insert neutrons.
Step 3: Construct the first orbital and fill it with up to 2 electrons.
Step 4: Construct the second orbital and fill it with up to 8 electrons.
Step 5: Construct the third orbital and fill it with up to 8 electrons.
One More Time!!
12
Mg
24.305
12p+
12n0
2e- 8e- 2e-
Step 1: Build the Nucleus – insert protons.
Step 2: Build the Nucleus – insert neutrons.
Step 3: Construct the first orbital and fill it with up to 2 electrons.
Step 4: Construct the second orbital and fill it with up to 8 electrons.
Step 5: Construct the third orbital and fill it with up to 8 electrons.