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NCERT Class 10 Science Metals and Non-metals: In-text questions (page 55) Solutions
AI-written, checked on 23 Oct 2026
Solutions written by Shishya, checked — not the board's official answers
Step-by-step working for every question of In-text questions (page 55) in NCERT's Class 10 Science book, chapter “Metals and Non-metals”, written by Shishya. Each question is in our own short words; open the NCERT chapter for the exact wording and figures.
How these were checked: the solutions were drafted with AI and then read and corrected on 23 Oct 2026. Every numerical final answer is recomputed from the question's own numbers by a calculator check that runs before each release; proofs and explanations were read, not machine-checked. The NCERT textbook is the authority — if something here disagrees with it, follow the book.
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In-text (page 55) Q1
Oxides of zinc, magnesium and copper were heated with zinc, magnesium and copper metals. In which cases do displacement reactions take place?
- Recall the reactivity series of metals: K, Na, Ca, Mg, Al, Zn, Fe, Pb, H, Cu, Ag, Au.
- A more reactive metal can displace a less reactive metal from its compound.
why?
A more reactive metal displaces a less reactive metal from a solution of its salt (reactivity series); a less reactive metal cannot displace a more reactive one.
- Zinc is more reactive than copper, so zinc displaces copper from copper oxide.
why?
A more reactive metal displaces a less reactive metal from a solution of its salt (reactivity series); a less reactive metal cannot displace a more reactive one.
- Magnesium is more reactive than zinc, so magnesium displaces zinc from zinc oxide.
why?
A more reactive metal displaces a less reactive metal from a solution of its salt (reactivity series); a less reactive metal cannot displace a more reactive one.
- Magnesium is more reactive than copper, so magnesium displaces copper from copper oxide.
why?
A more reactive metal displaces a less reactive metal from a solution of its salt (reactivity series); a less reactive metal cannot displace a more reactive one.
- Zinc is less reactive than magnesium, so zinc cannot displace magnesium from magnesium oxide.
why?
A more reactive metal displaces a less reactive metal from a solution of its salt (reactivity series); a less reactive metal cannot displace a more reactive one.
- Copper is less reactive than zinc, so copper cannot displace zinc from zinc oxide.
why?
A more reactive metal displaces a less reactive metal from a solution of its salt (reactivity series); a less reactive metal cannot displace a more reactive one.
- Copper is less reactive than magnesium, so copper cannot displace magnesium from magnesium oxide.
why?
A more reactive metal displaces a less reactive metal from a solution of its salt (reactivity series); a less reactive metal cannot displace a more reactive one.
Answer: Displacement reactions take place when zinc reacts with copper oxide, magnesium reacts with zinc oxide, and magnesium reacts with copper oxide.
In-text (page 55) Q2
Which metals do not corrode easily?
- Corrosion is the slow chemical attack on metals by substances like moisture, oxygen, and acids in the air.
- Metals that are less reactive do not react easily with these atmospheric substances.
- Gold and platinum are at the bottom of the reactivity series, so they do not react with oxygen or moisture.
- Therefore, gold and platinum do not corrode easily and keep their shine (silver tarnishes slowly).
Answer: Gold and platinum
In-text (page 55) Q3
What are alloys?
- An alloy is a homogeneous mixture of two or more elements.
- Usually, an alloy is a mixture of a metal with one or more other metals or non-metals.
- Alloys are made to improve properties like hardness, strength, or resistance to corrosion compared to pure metals.
Answer: An alloy is a homogeneous mixture of two or more metals, or of a metal and a non-metal (e.g. brass, bronze, steel), made to improve properties such as hardness, strength or resistance to corrosion.
Other exercises in this chapter
- In-text questions (page 40) — 2 questions
- In-text questions (page 46) — 5 questions
- In-text questions (page 49) — 2 questions
- In-text questions (page 53) — 3 questions
- End-of-chapter exercises — 16 questions
← Metals and Non-metals: notes, practice and all exercises
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