Question

Which of these ionic compounds have polyatomic ions? Check all that apply.

CaCO3
NaF
FeO
CaCl2
NaOH

Answer 1

A,E

Step-by-step explanation:

Answer 2

• CaCO₃ and
• NaOH.

Step-by-step explanation:

Polyatomic ions are ions that contain more than one atom in each one of the ions.

Ionic compounds are made of cations (positive ions) and anions (negative ion). By convention, the cation is written before the anion.

List the ions in each compound:

CaCO₃

Cation:
`\rm Ca^(2+)`,

Anion:
`\rm {CO_3}^(2-)`.

`\rm Ca^(2+)` is a monatomic ion for it contains only one atom in each ion.

`\rm {CO_3}^(2-)` is a polyatomic ion for it contains four atoms (one C atom and three O atoms) in each ion.

NaF

Cation:
`\rm Na^(+)`,

Anion:
`\rm F^(-)`.

Both
`\rm Na^(+)` and
`\rm F^(-)` are monatomic for they contain only one atom in each ion.

FeO

Cation:
`\rm Fe^(2+)`,

Anion:
`\rm {O}^(2-)`.

Both
`\rm Fe^(2+)` and
`\rm O^(2-)` are monatomic for they contain only one atom in each ion.

CaCl₂

Cation:
`\rm Ca^(2+)`,

Anion:
`\rm {Cl}^(-)`.

Both
`\rm Ca^(2+)` and
`\rm Cl^(-)` are monatomic for they contain only one atom in each ion.

NaOH

Cation:
`\rm Na^(+)`,

Anion:
`\rm {OH}^(-)`.

`\rm Na^(+)` is a monatomic ion for it contains only one atom in each ion.

`\rm {OH}^(-)` is a polyatomic ion for it contains two atoms (one O atom and one H atom) in each ion.