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PART II

What is the relationship between molecular modeling and mathematics?

The following exercise requires that you know how to use CHIME (online molecular modeling software). If you do not please review these labs first. Introduction to Molecular Modeling Using Chime

Let's begin with the two simple molecules, wate and carbon dioxide.

Rotate and zoom the two molecules. Notice that the three atoms in carbon dioxide (right side) form a linear molecule. That means the angle formed (with carbon as the vertex point is

Question 8: degrees
Does water form a linear molecule? No, water is a bent molecule.
Question 9: If oxygen is at the vertex what type of angle does the water molecule have (acute, obtuse or right angle)?

We can use CHIME to find the actual angles formed.

TRY THIS NOW!

 Hold down the right mouse button over the water molecule.----> Select ---> Mouse Click Action ---> AngleYou will see a check next to angle showing you can now measure the angle formed between three atoms (H-O-H) Click on the three atoms. On the bottom of screen you will see the angle.

What is the angle (to the nearest tenth degree) formed in a water molecule?
Question 10: degrees

Now try using CHIME
to measure the distances!

 Hold down the right mouse button over the water molecule. ---->Select ---> Mouse Click Action ---> DistanceYou will see a check next to distance showing you can now measure the distance formed between any two atoms. Click on any two atoms. On the bottom of screen you will see the distance in angstroms (written as a decimal)If you see 0.00 you did not click correctly;. Click outside the molecule a few times and try again..

Question 11: What is the distance in angstroms from each carbon to oxygen in the CO2 molecule shown above?

Question 12: What is the distance in angstroms from each hydrogen to oxygen in the H2O molecule?

Question 13: What is the distance from the tip of one hydrogen in a water molecule to the other hydrogen? (Click first on one hyrogen atom then the other.

If 1 angstrom = 10 -10 meters, approximately how many molecules of would it take to make a line of water 1 centimeter long?