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PART II

What is the relationship between molecular modeling and mathematics?

(-- See Part I if this is your first page view.)

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 JMol to find the actual angles formed.

TRY THIS NOW!

To measure angles

Double click on center of first atom, once on middle atom, twice on atom three.

  

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

 

Now try using JMol
to measure the distances!

 

To measure distance

Label the atoms: Right mouse button -->Labels --> With atom names

Double click on hydrogen (H33) then drag to oxygen (O28) -- double click 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?

GO TO PART III.