Ionic Bonding Mastery

Mastering Ionic Bonds!

What are Ions?

Atoms are usually neutral (same number of protons (+) and electrons (-)). However, atoms want a full outer electron shell (like noble gases - this is the Octet Rule). To achieve this, they can gain or lose electrons.

When an atom gains or loses electrons, it becomes an ion – an atom with an electrical charge.

Cations (+) and Anions (-)

  • Cations: Formed when atoms lose electrons. They become positively charged (more protons than electrons). Metals (like Sodium, Calcium, Iron) tend to form cations. Example: Na → Na⁺ + e⁻
  • Anions: Formed when atoms gain electrons. They become negatively charged (more electrons than protons). Non-metals (like Chlorine, Oxygen, Sulfur) tend to form anions. Example: Cl + e⁻ → Cl⁻

Ionic Bonding

Opposites attract! The positive cation and the negative anion are pulled together by strong electrostatic forces. This attraction forms an ionic bond, creating an ionic compound.

Ionic compounds form crystal lattice structures, not individual molecules.

Balancing Charges: The Goal!

Ionic compounds are electrically neutral overall. The total positive charge from the cations must exactly balance the total negative charge from the anions.

Example: Magnesium (Mg²⁺) and Chlorine (Cl⁻).

  • Mg has a +2 charge. Cl has a -1 charge.
  • You need TWO Cl⁻ ions (total charge -2) to balance ONE Mg²⁺ ion (total charge +2).
  • The formula is MgCl₂. The subscript '2' applies only to the Chlorine.

Polyatomic Ions: Some ions are groups of atoms bonded together with an overall charge (e.g., Sulfate SO₄²⁻). Treat them as a single unit when balancing charges. If you need more than one polyatomic ion, use parentheses: e.g., Ca(NO₃)₂.

Transition Metals: Metals like Iron (Fe) and Copper (Cu) can form ions with different charges (e.g., Fe²⁺ and Fe³⁺). Their names include a Roman numeral to show the charge: Iron(II) for Fe²⁺, Iron(III) for Fe³⁺.

How to Play

  1. Examine the available Cations (+) and Anions (-).
  2. Select ONE cation and ONE anion by clicking on them.
  3. Determine the lowest number (subscripts) of each ion needed to make the total charge ZERO.
  4. Enter these subscripts into the input boxes. (Use '1' or leave blank for a subscript of one).
  5. Look at the 4 possible names generated below the formula. Click the button with the CORRECT chemical name.
  6. Click "Check Answer". Get points for correct formula AND name selection!
  7. Use hints if needed, but they cost points!
  8. Earn badges and aim for the high score!