1) NH₃, N is a central atom.

a) Write acceptable Lewis structures for NH₃

b) Assign formal charges to the atoms in the Lewis structures for NH₃

c) Trough appropriate Lewis structures, show the resonance structures for NH₃

d) Determine the electron group geometry according to VSEPR for NH₃

e) Determine the molecular group geometry according to VSEPR for NH₃

f) Determine the point group of NH₃

g) Show all the symmetry elements of NH

h) Determine the polarity properties of NH₃

i) Has NH₃molecule optical activity properties?

j) Show the irreducible representations and related orbitals which involve in s and p bonding of NH₃.

k) Draw molecular orbital diagram of NH₃, show bond order and HOMO LUMO orbitals

2) H₂CO, C is a central atom.

3) BH₄^-, B is a central atom.