Writing Ionic Formulas

This video tutorial explains how to write formulas for ionic compounds, which are formed between metals and non-metals or cations and anions. It outlines three basic steps: identifying symbols, determining charges, and balancing them to write the formula. The video provides examples with sodium chloride, magnesium fluoride, chromium phosphide, and aluminum sulfate, demonstrating the application of these steps to create correct ionic formulas.

What is the first step in writing the formula for an ionic compound?

• Identify the type of bond

• Balance the charges

• Write down the symbol or formula of the elements

• Determine the charge of the elements

How many chlorine atoms are needed to balance the charge of one sodium atom in sodium chloride?

• Two

• Four

• One

• Three

In the formula for magnesium fluoride, what is the subscript for fluorine?

• Four

• Three

• Two

• One

What does the Roman numeral in chromium(II) phosphide indicate?

• The charge of the chromium ion

• The number of phosphorus atoms

• The charge of the phosphorus ion

• The number of chromium atoms

When writing the formula for aluminum sulfate, why is sulfate placed in parentheses?

• To indicate it is a polyatomic ion

• Because it is a single element

• To separate it from aluminum

• To show it has a charge of -1