Ionic Compounds and Their Properties

The video tutorial explains how to write the formula for aluminum sulfide by using the periodic table to identify the elements and their charges. It describes the ionic charges of aluminum and sulfur, and how to achieve a neutral compound by balancing these charges. The crisscross method is introduced to simplify the process of finding the correct formula, which is verified for accuracy. The tutorial concludes with a confirmation of the formula and a thank you from Dr. V.

What is the element symbol for aluminum on the periodic table?

• An

• Ag

• Au

• Al

Which type of compound is formed between a metal and a non-metal?

• Metallic

• Hydrogen

• Ionic

• Covalent

What is the ionic charge of aluminum?

• 2+

• 4+

• 1+

• 3+

What is the ionic charge of sulfur?

• 3-

• 2-

• 1-

• 4-

What method can be used to balance the charges in an ionic compound?

• Cross-multiply

• Elimination

• Crisscross

• Substitution

In the crisscross method, what do you do with the charges?

• Add them

• Subtract them

• Crisscross them

• Ignore them

How many sulfur atoms are needed to balance the charge with two aluminum atoms?

• 2

• 3

• 1

• 4

What is the net charge of a neutral compound?

• Variable

• Zero

• Negative

• Positive

What is the correct formula for aluminum sulfide?

• Al3S2

• Al2S3

• AlS

• AlS2