Ionic Compounds and Their Properties

The video tutorial explains how to write the chemical formula for sodium sulfide. It begins by identifying sodium and sulfur on the periodic table, noting that sodium is a metal and sulfur is a non-metal, forming an ionic compound. The tutorial then demonstrates how to balance the charges, as sodium has a +1 charge and sulfur has a -2 charge. By adjusting coefficients, the formula Na2S is derived. The crisscross method is used to verify the formula, ensuring the charges are balanced. The video concludes with a confirmation of the correct formula for sodium sulfide.

What is the symbol for sodium on the periodic table?

• So

• N

• Na

• S

What type of compound is formed when a metal and a non-metal combine?

• Covalent

• Ionic

• Molecular

• Metallic

What is the charge of a sulfur ion?

• -2

• +2

• -1

• +1

How many sodium ions are needed to balance the charge of one sulfur ion?

• Four

• Two

• One

• Three

What is the formula for sodium sulfide?

• NaS

• Na2S

• NaS2

• Na2S2

Which method can be used to verify the formula of an ionic compound?

• Crisscross method

• Substitution method

• Addition method

• Balancing method

What happens to the charges when using the crisscross method?

• They are added

• They are subtracted

• They are ignored

• They are swapped