Polyatomic Ions and Their Properties

The video explains that compounds can contain two different polyatomic ions. It introduces polyatomic ions, which have positive or negative charges and are made up of multiple atoms. Most polyatomic ions are anions, with ammonium being a common cation. The video provides examples of ionic compounds formed by ammonium ions bonding with other polyatomic ions, such as nitrate and phosphate, emphasizing the need for charge balance in these compounds.

What is a characteristic feature of polyatomic ions?

• They are made of a single atom.

• They have either a positive or negative charge.

• They are always positively charged.

• They are always negatively charged.

Which of the following is true about most polyatomic ions?

• They have no charge.

• They are neutral.

• They are positively charged.

• They are negatively charged.

What is the charge of the ammonium ion (NH4+)?

• Negative

• Positive

• Variable

• Neutral

Which negative polyatomic ion can ammonium ion bond with to form ammonium nitrate?

• Phosphate

• Sulfate

• Carbonate

• Nitrate

What is the formula for ammonium nitrate?

• NH4NO3

• NH3NO4

• NH3N

• NH4N

What type of compound is formed when ammonium ion bonds with a negative polyatomic ion?

• Molecular compound

• Metallic compound

• Ionic compound

• Covalent compound

How many ammonium ions are needed to balance the charge of one phosphate ion?

• Four

• Three

• One

• Two

What is the charge of the phosphate ion?

• 1-

• 2-

• 3-

• 4-

What is the correct formula for ammonium phosphate?

• NH4(PO4)3

• (NH4)3PO4

• NH4PO4

• (NH4)2PO4

Why is it necessary to balance charges in ionic compounds?

• To make the compound dissolve in water.

• To increase the compound's weight.

• To make the compound colorful.

• To ensure the compound is stable.