Part a what are the electron and molecular geometries, respectively, for the carbonate ion, co3 2-?

The electronic geometry for the carbonate ion, in CO₃²⁻ is trigonal planar, and molecular geometry will be trigonal planar.

The electronic geometry = Total number of atoms + lone pair around the central atom

= 3 atoms + 0 lone pair

= sp₂ (trigonal planar)

The molecular geometry = As there is no lone pair its geometry will be trigonal planar.