Mastering the Criss-Cross Method for Ionic Formulas

The video tutorial explains the crisscross method for writing formulas of ionic compounds. It covers examples like calcium chloride, aluminum bromide, and calcium oxide, demonstrating how to balance charges. The tutorial also extends the method to polyatomic ions, using calcium nitrate as an example. Viewers are encouraged to practice and use additional resources for better understanding.

What is the ionic charge of calcium?

• 1-

• 2+

• 1+

• 2-

What is the correct formula for calcium chloride using the crisscross method?

• CaCl2

• Ca2Cl

• Ca2Cl2

• CaCl

What is the ionic charge of aluminum?

• 3+

• 1+

• 2+

• 1-

What is the correct formula for aluminum bromide using the crisscross method?

• AlBr

• AlBr2

• AlBr3

• Al3Br

When reducing subscripts, what is the formula for calcium oxide?

• CaO

• Ca2O

• Ca2O2

• CaO2

What is the ionic charge of phosphorus in aluminum phosphide?

• 1+

• 3-

• 3+

• 2-

Tags

NGSS.HS-PS1-1

What is the correct formula for aluminum phosphide after reducing subscripts?

• AlP3

• Al3P

• AlP

• Al3P3

What is the formula for the nitrate ion?

• NO3+

• NO3-

• NO2-

• NO4-

What is the correct formula for calcium nitrate using the crisscross method?

• Ca(NO3)2

• CaNO3

• Ca2(NO3)3

• Ca(NO3)3

What is the correct formula for calcium phosphate using the crisscross method?

• Ca(PO4)2

• Ca2(PO4)3

• Ca3(PO4)2

• Ca3(PO4)3