The dipole moment of compound AB is 10.92 D and that of compound CD is 12.45 D. If the bond length of AB is 2.72 A° and that of CD is 2.56 A°, then for these compounds the correct statement is:
1.  More ionic nature in AB
2.  More ionic nature in CD
3.  Equal in both
4.  Cannot be predicted

H₂O is dipolar, whereas BeF₂ is not. It is because:
 

Which of the following would have a permanent dipole moment:

1. BF₃

2. SF₄

3. SiF₄

4. XeF₄