Classic
Chem
So, what
kind of
bond will
be made?
9-12 Science Std: Chem 2a
We have covered:
The parts of an atom:
We have covered:
How the periodic table was made
We have covered:
The names of some groups…
We have covered:
The trends of some properties
We have covered:
Some information about valence electrons
electron
neutron
proton
We have covered
Types of bonds
Covalent, Polar Covalent,
Ionic, Metallic
And how they work
We have covered
And the Octet Rule
To see if the atoms
will bond
So now we need to see
If the atoms are going to bond…
What kind of bonds are they going to make?
Covalent, Polar Covalent or Ionic?
Here’s how we find out
Remember Electronegativity?
The ability of an atom to pull on electrons?
Fluorine is the highest
Gets smaller like this
Here’s how we find out
Here is your own copy of a periodic chart
That has the electronegativity printed on it
Here’s how we find out
Electronegativity of each element
Is shown here for each element
How does this help us
Electronegativity is like a game…
…a game of “Tug-of-War”
How does this help us
If you are evenly matched
The knot stays in the middle
How does this help us
If one side is a little stronger….
The knot moves more to one side
How does this help us
If one side is a lot stronger….
The knot moves all the way
This works the same in bonds
They play “tug-of-war”
They do it with electrons in bonds
This works the same in bonds
If the atoms are equal….
The electrons spend equal time
Covalent Bond
This works the same in bonds
If one atom is a little stronger
The electron spends more time with one
Polar
Covalent
This works the same in bonds
If one atom is a lot stronger
The electron moves to that atom
Ionic Bond
How can we tell the strength?
Electronegativity of the atom
Compare the electronegativity
Get the type of
bond
Here’s how it works
Atom 1
Atom 2
3.8
1.4
2.4
Subtract the 2 values
And compare to a chart to get the type of bond
Here’s how it works
If the answer is
0.0 – 0.3
Covalent Bond
0.3 – 1.7
Polar Covalent Bond
1.7 – 4.0
Ionic Bond
That’s all there is to it…..
Now it’s your turn
Time for another exercise
Yes….. Another worksheet
Now it’s your turn
Using your new periodic table
Fill in the information on the worksheet
Your Homework…..
Finish your
Bond
Worksheet
to turn in
tomorrow
You have a tool to help you
Bond calculator
Here’s how it works
Find the larger electronegativity on the
outside wheel
Find the smaller electronegativity on the
inside wheel
Here’s how it works
Rotate the inner wheel until the smaller
number
Is under the larger number on the outer
wheel
Here’s how it works
Read the type of bond in the little window
C = Covalent, P = Polar Covalent, I = Ionic