Questions

The resting place of Morarji Desai is Abhay Ghat.

Hard copy is the output which is printed by the computer.

rift valley

Lagoons are formed along the coasts by the action of winds and waves. They are commonly found off the deltas of large rivers such as the Nile and Ganges.

You have to consider three things.

1. First, are the bonds polar?

Look at differences in electronegativity and if  it is >0.5, bonds are polar.

2. Second, does the molecule have unshared electron pairs?

If so, they generally lead to a polar molecule.

3. Third, is the molecule symmetric?

If so, then although the bonds may be polar, the symmetry cancels out the individual bond polarity and the molecule is non polar.

CF4 follows all the rules above and has a symmetric distribution of charge, making it nonpolar. The others all have asymmetric charge distributions.

Hence, CF4 represents a Non-polar molecule.