Question

What is polyatomic ions?

Answer 1

An ion is polyatomic if it contains more than one atoms.

Step-by-step explanation:

The prefix "poly-" in the word polyatomic means "more than one." A polyatomic ion contains more than one atoms. Note that these atoms might belong to the same element. For example, in the book Foundations of Introductory College Chemistry, the triiodide ion
`\rm {I_3}^(-)` (note the subscript) is also classified as "polyatomic."

Other (more common) examples include:

• the sulfate ion,
  `\rm {SO_4}^(2-)`, which contains five atoms, and
• the hydroxide ion,
  `\rm OH^(-)`, which contains two atoms.

In contrast, an ion is monatomic (with the prefix "mono-") if it contains only one atom. Examples include:

• the chloride ion,
  `\rm Cl^(-)`,
• the iodide ion,
  `\rm I^(-)` (without the subscript,) and
• the sodium ion,
  `\rm Na^(+)`