What types of elements are shown in the polyatomic ions in model 1?

These ions are disjoint by the charge on the ion into four dissimilar tables and listed alphabetically within each table. Each polyatomic ion, has it called, chemical, formula, two dimensional drawing, and three dimensional representation are given.
The three dimensional buildings are drawn as CPK models. CPK structures represent the atoms as sphere, where the radius of the sphere is equal to the van der waals radius of the atom; these buildings give a measure up the volume of the polyatomic atom.

Determine the  wavelength of light emitted when an electron  in an li2+ ion  makes a transition from an orbital with n  =  6 to an orbital with n  = 5.