What is a polyatomic ion? Consulting p.117 in text, list the formulas and names of at least 10 polyatomic ions. When writing the overall formula of an ionic compound involving polyatomic ions, why are parentheses used around the formula of a polyatomic ion when more than one such ion is present? Give an example.

The answer to your question is below

Explanation:

Polyatomic ions are ions composed for more than 1 atom. There are polyanions and polycations.

Polyanions have a negative charge and polycations have a positive charge.

Examples

                      Polyanions                             Polycations

  acetate           CH₃COO⁻        ammonium      NH₄⁺¹                                    

  bromate          BrO₃⁻

  chlorate           ClO₃⁻

  hydroxide        OH⁻

  nitrate              NO₃⁻

  nitrite               NO₂⁻

  sulfate             SO₄⁻²

  phosphate      PO₄⁻³

  permanganate  MnO₄⁻

We write parentheses before or after a polyatomic ion to emphasize that the oxidation number of the atom which interacts with it affects all the atoms that form part of the polyatomic ion.

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.