Polyatomic Ion Calculator

What is a Polyatomic Ion?

A polyatomic ion is a molecule consisting of two or more atoms that behave as a single unit and carry an electric charge. These ions play a crucial role in chemistry, particularly in the formation of ionic compounds and in solution chemistry.

Formula and Representation

Polyatomic ions are represented by their chemical formula, which shows the constituent atoms and the overall charge. For example:

• \(\text{NH}_4^+\) (ammonium ion)
• \(\text{SO}_4^{2-}\) (sulfate ion)
• \(\text{CO}_3^{2-}\) (carbonate ion)

Where:

• The subscripts indicate the number of each atom
• The superscript shows the overall charge of the ion

Calculation Steps

To determine the formula of an ionic compound containing a polyatomic ion, follow these steps:

1. Identify the cation (positive ion) and its charge
2. Identify the polyatomic anion (negative ion) and its charge
3. Balance the charges to create a neutral compound
4. Write the formula, placing the cation first

Example Calculation

Let's form a compound with calcium (Ca²⁺) and the nitrate ion (NO₃⁻):

1. Cation: Ca²⁺
2. Polyatomic anion: NO₃⁻
3. To balance: (2+) + 2(1-) = 0
4. Formula: Ca(NO₃)₂

Visual Representation

Here's a visual representation of the formation of calcium nitrate:

This diagram illustrates:

• The calcium cation (Ca²⁺) in blue
• Two nitrate anions (NO₃⁻) in green
• The ionic bonds between the cation and anions (red lines)
• The resulting neutral compound: calcium nitrate, Ca(NO₃)₂