Bonding & StructureDeep Dive

Understanding Ionic Bonding Step by Step

Part of Ionic BondingGCSE Chemistry

This deep dive covers Understanding Ionic Bonding Step by Step within Ionic Bonding for GCSE Chemistry. Revise Ionic Bonding in Bonding & Structure for GCSE Chemistry with 27 exam-style questions and 20 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 2 of 13 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 2 of 13

Practice

27 questions

Recall

20 flashcards

🔬 Understanding Ionic Bonding Step by Step

Let's walk through sodium chloride (NaCl) — table salt:

Step 1: Sodium atom (Na)
• Electron configuration: 2,8,1
• Has 1 electron in outer shell
• Wants to lose this electron to get 2,8 (like neon)
• 11 protons, 11 electrons → neutral
Step 2: Chlorine atom (Cl)
• Electron configuration: 2,8,7
• Has 7 electrons in outer shell — needs 1 more!
• Wants to gain 1 electron to get 2,8,8 (like argon)
• 17 protons, 17 electrons → neutral
Step 3: Electron Transfer
• Sodium's outer electron jumps to chlorine
• This is a chemical reaction — atoms change!
• Neither atom is neutral anymore
Step 4: Ions Form
• Sodium: 11 protons, 10 electrons → Na⁺ (positive ion = CATION)
• Chlorine: 17 protons, 18 electrons → Cl⁻ (negative ion = ANION)
• Both now have full outer shells!
Step 5: Ionic Bond Forms
• Na⁺ and Cl⁻ are oppositely charged
• Opposite charges attract (electrostatic attraction)
• This attraction IS the ionic bond
• Very strong — takes lots of energy to break!

Why do Group 1 metals form +1 ions? They have 1 outer electron to lose.
Why do Group 2 metals form +2 ions? They have 2 outer electrons to lose.
Why do Group 7 elements form -1 ions? They need 1 electron to complete their shell.
Why do Group 6 elements form -2 ions? They need 2 electrons to complete their shell.

The Charge Rule: The charge on an ion = number of electrons lost or gained. Metals lose electrons (positive charge), non-metals gain electrons (negative charge). The number equals how far they are from a full shell!

Keep building this topic

Read this section alongside the surrounding pages in Ionic Bonding. That gives you the full topic sequence instead of a single isolated revision point.

Practice Questions for Ionic Bonding

Which combination of elements forms an ionic compound?

  • A. Sodium and chlorine
  • B. Carbon and hydrogen
  • C. Nitrogen and oxygen
  • D. Carbon and oxygen
1 markfoundation

Describe the structure of an ionic compound and explain why ionic compounds have high melting points. [3 marks]

3 marksstandard

Quick Recall Flashcards

What is an anion?
A negative ion (formed when non-metals gain electrons)
What is a cation?
A positive ion (formed when metals lose electrons)

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