NH3 has higher dipole movement than NF3 becz. H is less electro negative than F

**Dipole Moments of NH3**

NH3, also known as ammonia, is a polar molecule. It has a trigonal pyramidal molecular geometry with the nitrogen atom at the center and three hydrogen atoms and one lone pair of electrons surrounding it.

**Electronegativity Difference**
The polarity of a molecule is determined by the electronegativity difference between its constituent atoms. Electronegativity is the ability of an atom to attract electrons towards itself in a chemical bond. In NH3, nitrogen is more electronegative than hydrogen, causing the nitrogen atom to pull the shared electrons in the N-H bonds closer to itself.

**Polar Bonds**
Each N-H bond in NH3 is polar due to the electronegativity difference between nitrogen and hydrogen. The nitrogen atom attracts the bonding electrons more strongly, creating a partial negative charge on the nitrogen atom and a partial positive charge on each hydrogen atom.

**Net Dipole Moment**
The dipole moment is a measure of the overall polarity of a molecule. It is the product of the charge (or partial charge) on an atom and the distance between the charges. In NH3, the individual dipole moments of the N-H bonds do not cancel each other out because of the molecular geometry.

The lone pair of electrons on nitrogen creates an uneven distribution of electron density, causing the molecule to have a net dipole moment. The dipole moment vector points from the nitrogen atom towards the hydrogen atoms, indicating that the molecule has a positive end (hydrogens) and a negative end (nitrogen).

**Dipole Moments of NF3**

NF3, also known as nitrogen trifluoride, is also a polar molecule. It has a trigonal pyramidal molecular geometry with the nitrogen atom at the center and three fluorine atoms surrounding it.

**Electronegativity Difference**
In NF3, nitrogen is more electronegative than fluorine, resulting in polar N-F bonds. The fluorine atoms attract the shared electrons more strongly than nitrogen, creating partial negative charges on the fluorine atoms and a partial positive charge on nitrogen.

**Polar Bonds**
Each N-F bond in NF3 is polar due to the electronegativity difference between nitrogen and fluorine. The nitrogen atom pulls the bonding electrons closer to itself, resulting in a partial negative charge on nitrogen and partial positive charges on the fluorine atoms.

**Net Dipole Moment**
Similar to NH3, the dipole moments of the individual N-F bonds in NF3 do not cancel each other out due to the molecular geometry. The lone pair of electrons on nitrogen causes an asymmetric distribution of electron density.

As a result, NF3 has a net dipole moment. The dipole moment vector points from nitrogen towards the fluorine atoms, indicating that the molecule has a positive end (fluorines) and a negative end (nitrogen).

In summary, both NH3 and NF3 molecules have dipole moments due to the presence of polar bonds. The molecular geometries of these molecules prevent the individual dipole moments from canceling out, resulting in a net dipole moment. Therefore, both NH3 and NF3 are polar molecules.