Answer
1) The lewis structure is drawn the way the molecular formula is written.
2) In the N-H bonds the dipole moment is towards Nitrogen. The molecular dipole is canceled.
3) The compound has a zero dipole moment.
Work Step by Step
1) The four hydrogens are drawn attached to nitrogen. There are no lone pairs on nitrogen.
2) In the N-H bonds the dipole moment is towards nitrogen because Nitrogen is more electronegative than hydrogen. Thus, there is no molecular dipole because in its tetrahedral shape, all of the atoms bonded to the central nitrogen atom are identical and all the directions are equivalent. Therefore, the 4 bond dipoles cancel each other
3) The compound has a zero dipole moment because all the dipole are canceled.
