Question 7
Give a reason why – properties of metals are related to their activity or reactivity series of metals. Explain the same with reference to potassium and iron in the series.
Activity series of metals is a series of arrangement of metals in order of their reactivity. The most active metal is at the top of the series & the least active metal is at the bottom of the series.
Potassium is at the top of the series, hence it is the most reactive metal. It reacts vigorously even with cold water and explosively with acids to liberate hydrogen gas.
Iron lies in the middle of the series at number 7, hence it is moderately reactive. It does not react with cold water but reacts smoothly with steam and less vigorously with acids to liberate hydrogen gas.
ICSE Class VII Chemistry Chapter 5 14 Marks
Metals and Non-Metals — Quick Study Guide
Elements are broadly classified as metals, non-metals, or metalloids based on their physical and chemical properties.
Key Properties
- Metals: Lustrous, malleable, ductile, sonorous, good conductors, high density
- Non-metals: Dull, brittle, poor conductors, non-sonorous, low density
- Metalloids: Properties of both (e.g., Silicon, Germanium)
Chemical Reactions
- Metal + O2 → Basic oxide (turns red litmus blue)
- Non-metal + O2 → Acidic oxide (turns blue litmus red)
- Metal + Acid → Salt + H2
Exam Tips
- Know all exceptions: Mercury (liquid), Graphite (conducts), Diamond (lustrous), Na/K (soft)
- Learn the comparison table (8 properties) thoroughly
- Practice writing equations for metal reactions
- Know uses of at least 5 metals and 5 non-metals
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