Revision activities / Chemistry study practice
Learning focus: Inorganic Chemistry. This original Grade 11 Chemistry exercise gives you a task, a suggested response and a follow-up challenge. It is classroom practice, not an official assessment paper.
Understand the idea
An ionic compound is electrically neutral overall. Formula writing balances positive and negative charges in the smallest whole-number ratio.
Try the activity
Write the formulae of magnesium chloride and aluminium oxide. Explain the charge balance in each.
Attempt your response before opening the guidance. Show the steps, textual evidence or reasons that support your answer; a final answer alone may hide a misunderstanding.
Your practice workspace
Your work and progress stay in this browser. Use Clear this activity to remove saved work.
Show suggested answer and reasoning
Magnesium forms Mg²⁺ and chloride is Cl⁻, so MgCl₂ has one magnesium ion for two chloride ions. Aluminium forms Al³⁺ and oxide is O²⁻, giving Al₂O₃ because +6 and −6 balance.
Follow-up challenge
Try calcium oxide and aluminium chloride. Explain why charge numbers should not simply be added together to produce a formula.
Review your work
- Did you answer the question actually asked?
- Can you explain the method or evidence in your own words?
- What would you change if one condition in the task changed?
Use the suggested response to identify one correction, then attempt the task again without copying it. For an open-ended question, other well-supported answers may be reasonable. Ask your teacher to check interpretations or language forms where needed.
Continue Chemistry practice
Back to the subject guide · Check available member notes and downloads
Match this activity to the learning outcomes and sequence in your school’s current Grade 11 curriculum-design collection. This activity is a focused learning example, not a complete curriculum map.
WhatsApp us