Chemistry · Bonding, Structure and Properties of Matter
Ionic Bonding
Spec 5.2.1.2📙 Higher
Interactive · transfer electrons step by step
Theory · read, then commit
Ionic bonding happens between a metal and a non-metal. The metal transfers its outer electrons to the non-metal, and the oppositely charged ions that form attract one another.
Checkpoint · quick check
Sodium (2.8.1) reacts with chlorine (2.8.7) to form sodium chloride. Describe what happens to the electrons.
Which ion does an atom form?
➕Metals → positive ions
Group 1 → +1 (Na⁺), Group 2 → +2 (Mg²⁺), Group 3 → +3 (Al³⁺).
➖Non-metals → negative ions
Group 7 → −1 (Cl⁻), Group 6 → −2 (O²⁻), Group 5 → −3 (N³⁻).
⚖️Charges must balance
An ionic compound is overall neutral — MgCl₂ needs two Cl⁻ for one Mg²⁺.
Checkpoint · quick check
Determine the formula of calcium chloride. (Calcium is in Group 2, chlorine is in Group 7.)
⚠️ Common Mistake
Students often say the ionic bond IS the transfer of electrons from the metal to the non-metal. That is not the bond: the transfer is a one-off event that only creates the ions. The ionic bond itself is the strong electrostatic attraction between the oppositely charged ions produced. Remember too that these charges must balance, so every ionic compound has an overall charge of zero.
Retrieval · Match the Ion to its Charge
Test yourself · 10 questions, exam order
⭐Examiner Tip
Describing how an ionic bond forms, don't stop at "electrons transfer" — that only makes the ions. The bond is the strong electrostatic attraction between the oppositely charged ions. Then check the charges balance to an overall zero.
0 of 10 answered
Warm-up · 2 questions
Explain why an ionic compound such as sodium chloride has no overall electrical charge.
Explain, in terms of electron arrangement, why metals form positive ions but non-metals form negative ions.
Exam standard · 4 questions
Describe how a dot-and-cross diagram represents the formation of the ions in sodium chloride.
Magnesium reacts with chlorine. Deduce the formula of the compound formed and justify it using the ion charges.
A student writes: 'The ionic bond is the transfer of electrons from sodium to chlorine.' Explain why this statement is not correct.
Potassium reacts with oxygen. Predict the formula of potassium oxide and justify your answer using ion charges. (K is Group 1, O is Group 6.)
Stretch · 4 questions
Explain why the noble gases in Group 0 do not normally form ions.
Explain, in terms of electron transfer, why the formula of aluminium oxide is Al₂O₃.
A compound is made of ions X²⁺ and Y³⁻. Deduce its formula and explain how you worked it out.
Explain one limitation of using a dot-and-cross diagram to represent solid sodium chloride.
Key note · cover it, say it, check it
Revision card · 6 stepsIonic Bonding
01Ionic bonding: metal loses electrons → positive ion.
02Non-metal gains electrons → negative ion.
03Opposite charges attract → ionic bond.
04Both achieve full outer shells.
05Group number tells you charge: Group 1 → +1, Group 7 → −1 etc.
06Overall compound charge = zero.
Exam ladder · Ionic Bonding
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