Writing Ionic Compound Formulas

Anion

A negatively charged ion, anions form from those on the right (except the noble gases) of periodic table

When Do You Use a Roman Numeral

Any transition metal compound can have several ion forms, such as iron, which can ionize to form either Fe2+ or Fe3+. Determine the symbol for the transition metal in the chemical formula. (First Symbol). Determine what transition metal is represented by the symbol in the formula using the periodic table. Determine the charge of the transition metal ion. In order to do this, use the subscript of the anion as the positive charge of the transition metal ion and the subscript of the metal ion as the negative charge of the anion. In naming the transition metal ion, add a Roman numeral in parenthesis after the name of the transition metal ion. The Roman numeral must have the same value as the charge of the ion. Add the name of the anion to the transition metal ion.

Ion

Atom with an uneven amount of electrons.

When Writing Names, Always

CATION THEN ANION

Ionic Charge

Metals (left) will be positive. Non metals (Right) will be negative.

Mono atomic cation names

Name of Ion (the calcium part of calcium chloride or CaCl2)

Using subscripts when Balancing charges

Number of atoms in a ion

Cation

Positively charged ion, Usually on the left of the Periodic table.

Mono Atomic Cation Names

Root + IDE (the chloride part of calcium chloride or CaCl2)

How can you tell if charges are balanced

The easiest compounds to charge are the ones with a 1:1 charge ratio. Li1+ Bonds with Cl1- to form LiCl. Mg2+ bonds with O2- to form MgO. Al3+ bonds with N3- to form AlN. When you don't have a 1:1 ratio you have to find the combination that balances all of the charges. Li1+bonds with O2- to form Lithium oxide, Li2O Mg2+ bonds with N 3- to form Magnesium nitride, Mg3N2. Al3+ bonds with Cl1-to form Aluminum chloride, AlCl3

Polyatomic or Nah?

You can decide if an atom is poly atomic or not by

Using Brackets when Balancing Charges

You use brackets to group an ion before adding an extra charge so that you can balance out the charges.