Naming Ionic Compounds Science 10

Simple Ionic Compounds The rules: Name the first element This is always the metal (cation) The name stays as it appears on your periodic table Name the second element This is always the non-metal (anion) The name will be similar to that on the periodic table with the ending –ide

The two element names are put together with a space in the middle We ignore any numbers in the name – they are only there to make the charges equal

Ions of Non-metals Element Ion Symbol fluorine fluoride F- chlorine chloride Cl- bromine bromide Br- iodine iodide I- oxygen oxide O2- sulphur sulphide S2- selenium selenide Se2- nitrogen nitride N3- phosphorus phosphide P3-

Example KBr CaF2 First = potassium Second = bromide Name: potassium bromide CaF2 First = calcium Second = fluoride Name: calcium fluoride

You Try MgCl2 CaO Sc2O3 Na2O

Ionic Compound with Multivalent Elements Some elements are able to form more than one ion – they are called multivalent Example: Copper can be Cu+ or Cu2+ meaning it can donate 1 or 2 electrons On your periodic table of ions, both charges will be shown

When compounds are made with multivalent elements, we must indicate which charge is used. This is done by writing the roman numeral of the charge next to the name of the cation Example: FeO Fe2+ is required to balance with O2- The name is: iron(II) oxide

You Try MnCl2 Ni2S3 CuO CuBr2

Writing a Chemical Formula If you’re given the name, can you write the formula? Rules: First: find the ion for the first element Second: find the ion for the second element Third: use the criss-cross rule to make the formula

Line three = chemical formula Three Line Method The three line method helps us do this Line one is the name Line two are the ions Line three is the chemical formula Line one = name Line two = ions Line three = chemical formula

Example strontium nitride sodium oxide strontium nitride sodium oxide

Example - Answers strontium nitride sodium oxide strontium nitride Sr2+ N3- Sr3N2 sodium oxide Na+ O2- Na2O

Write the formula’s for: You Try Write the formula’s for: calcium oxide potassium sulphide zinc chloride copper(I) phosphide

Naming Ionic Compounds With Polyatomic Ions

Polyatomic Ions Polyatomic ions are ions that contain two or more atoms. They have a charge which means that they will gain and lose electrons This allows them to be part of an ionic compound A list of polyatomic ions is found on the back of your periodic table

Naming with Polyatomic Ions It is the same for naming ionic compounds BUT you must use the names of the polyatomic ions. The endings will not change to –ide Examples: LiOH NH4Cl BaSO3

Writing Formula’s When there is more than one of the polyatomic ion needed you must place it in brackets Example: lithium hydroxide Example: calcium hydroxide

You Try Write the name or formula for the following: sodium hydroxide Sr(NO2) magnesium nitrate NaPO4 calcium carbonate