Ionic Compounds and Their Formulas

The video tutorial explains how to write formulas for ionic compounds. It covers the steps of identifying the symbols and charges of metal and non-metal ions using the periodic table, handling polyatomic ions, and applying the crisscross method. Examples include magnesium chloride, sodium sulfate, potassium sulfide, calcium carbonate, and iron III oxide, demonstrating the application of these steps in different scenarios.

What is the first step in writing formulas for ionic compounds?

• Identify the charge of the non-metal ion

• Write the symbol and charge of the metal ion

• Use the crisscross method

• Find the polyatomic ion formula

How do you determine the charge of a metal ion?

• By its color

• By its atomic number

• From the periodic table

• By its melting point

What is the formula for magnesium chloride?

• Mg2Cl

• Mg2Cl2

• MgCl2

• MgCl

What does the ending 'ate' or 'ite' in a compound name indicate?

• An element from group 1

• A metal ion

• A non-metal ion

• A polyatomic ion

What is the formula for sodium sulfate?

• NaSO3

• Na2SO3

• Na2SO4

• NaSO4

What is the charge of sulfur when it forms sulfide?

• -1

• -2

• +1

• +2

What is the formula for potassium sulfide?

• KS

• K2S

• KS2

• K2S2

What does a Roman numeral in a compound name indicate?

• The group number

• The charge of the metal ion

• The number of atoms

• The atomic mass

What is the formula for calcium carbonate?

• CaCO2

• Ca(CO3)2

• Ca2CO3

• CaCO3

What is the formula for iron(III) oxide?

• FeO3

• Fe2O3

• FeO

• Fe3O2