The shape of a moleculs is determined by electron pair repulsions in the valence shell. A lp occupies a larger space than a bp because it is not shared by two nuclei The the lp lp repulsion is greater than the lp-bp repulsion, which in turn is greater the bp-bp repulsion. The presence of lp causes distortion of bond angles hence, a daviation from an ideal shape. The extent of distortion depends upon the orientation of the lp's around the central atom In a trigonal bipyramid, The lp's occupy equatorial positions than the apical ones In `AB_(n)` type molecules, as the `EN` of A increases, the bp's come closer and the repulsion between them increases. On the other hand, as `EN` of `B` increases, the lp s get farther and repulsion decreases
Which of the following statements is true ?

Options

A. `F-N-F` angle in `NF_(3)` is greater than `H-N-H` angle in `NH_(3)` .
B. `F-N-F` angle in `NF_(3)` is smaller than `H-N-H` angle in `NH_(3)` .
C. `H-O-H` angle in `H_(2)O` is greater than `H-N-H` angle in `NH_(3)` .
D. `F -O-F` angle in `F_(2)O` is greater than `H-O-H` angle in `H_(2)O` ..

Explanation

To determine which statement is true regarding the bond angles in the given molecules, we will analyze the molecular shapes and the factors affecting the bond angles based on the presence of lone pairs and electronegativity.

### Step-by-Step Solution:

1. **Identify the Molecules and Their Structures**:
- We have three molecules to analyze: NF3 (Nitrogen Trifluoride), NH3 (Ammonia), H2O (Water), and F2O (Difluorooxide).
- NF3 and NH3 both have a nitrogen central atom with one lone pair and three bond pairs.
- H2O has an oxygen central atom with two lone pairs and two bond pairs.
- F2O also has an oxygen central atom with two lone pairs and two bond pairs, but with fluorine atoms bonded to it.

2. **Analyze Bond Angles in NF3 and NH3**:
- In NH3, the bond angle (H-N-H) is approximately 107 degrees.
- In NF3, the bond angle (F-N-F) is approximately 101.9 degrees.
- The presence of a lone pair in both molecules causes distortion from the ideal tetrahedral angle (109.5 degrees).
- However, since fluorine is more electronegative than nitrogen, the bond pairs in NF3 are pulled closer to the fluorine atoms, resulting in a smaller bond angle compared to NH3.

3. **Compare Bond Angles in H2O and NH3**:
- In H2O, the bond angle (H-O-H) is approximately 104.5 degrees.
- The presence of two lone pairs in H2O leads to greater lone pair-lone pair repulsion, which reduces the bond angle compared to NH3.

4. **Analyze Bond Angles in F2O**:
- In F2O, the bond angle is influenced by the electronegativity of fluorine, which pulls the bond pairs away from the oxygen.
- The bond angle in F2O is smaller than in H2O due to the greater distance between the bond pairs caused by the electronegativity of fluorine.

5. **Conclusion**:
- The correct statement is that the bond angle in NF3 is smaller than in NH3, which is true.
- The bond angle in H2O is less than that in NH3 due to the presence of lone pairs causing greater repulsion.
- The bond angle in F2O is also less than that in H2O due to the influence of electronegativity.

### Final Answer:
The true statement is: **The bond angle F-N-F in NF3 is smaller than the H-N-H bond angle in NH3.**