Question

the lewis electron dot structure for water shows 4 regions of electron density, reds, around the central o atom. two of the reds come from bonding electron pairs shared between the o and the two h atoms. the other two reds come from the nonbonding electron pairs on the o atom. electron pairs repel one another and this is what determines a molecules shape. the perfect geometric shape containing 4 \points\ would be a tetrahedron with 4 sides. the bond angles in the perfect tetrahedron would be 109.5°. water is not perfect since the 4 points are not the same, but it gives us an approximation. the machine used to determine molecular shape is called the x - ray diffractometer. this machine sees atoms but not nonbonding electron pairs. the machine sees water as a bent shape with bond angles approximately 109.5°. water has 1 reds, 2 are from bonding electron pairs and 3 are from nonbonding electron pairs. the shape is 4 and the approximate bond angles are 5°. a. 0 b. 1 c. 2 d. 3 e. 4 f. 5 g. 6 h. atoms i. diatomic j. planar trigonal k. tetrahedral l. pyramidal m. bent n. 109.5 o. 120 p. 90 q. 180 r. 60

Explanation:

The text clearly states that water has 4 REDs. Two of them are from bonding electron pairs (shared between O and H) and two from non - bonding electron pairs on O. The machine sees water as bent - shaped, and the approximate bond angle is given as an approximation of the tetrahedral angle (109.5°).

Answer:

1. E. 4
2. C. 2
3. C. 2
4. M. bent
5. N. 109.5