Potassium is in Group 1 of the Periodic Table.
Potassium reacts with water to make potassium hydroxide, KOH\text{KOH}KOH, and hydrogen.
Write the balanced symbol equation for the reaction between potassium and water.
Potassium ions, K+\text{K}^+K+, are formed when potassium reacts with water.
Look at the equation. It shows how a potassium ion is formed from a potassium atom:
K−e−→K+ \text{K} - \text{e}^- \rightarrow \text{K}^+ K−e−→K+The symbol e−\text{e}^-e−, means an electron.
The formation of a potassium ion from a potassium atom is an example of oxidation.
Explain why.
Caesium is another element in Group 1.
Caesium reacts much faster than potassium does.
Explain why. Use ideas about electrons in your answer.
41 exam-style questions on OCR GCSE Chemistry Predicting chemical reactions. Each one has a worked solution and a mark scheme showing where the marks go.