--- title: "NCERT Solutions Class 7 Science The World of Metals and Non-metals" url: https://www.swavid.com/science/class/7/chapter/the-world-of-metals-and-non-metals/ncert-solutions dateModified: 2026-10-07T16:05:09+00:00 --- # NCERT Solutions Class 7 Science The World of Metals and Non-metals This chapter's questions cover the physical and chemical properties of metals and non-metals, including malleability, ductility, sonority, conduction of heat and electricity, and their reactions with air and water. Free PDF (6 pages): https://www.swavid.com/api/seo/pdf/ncert/science/class-7/swavid-ncert-solutions-class-7-science-chapter-4-the-world-of-metals-and-non-metals-c2ee4b08ea.pdf ## Let Us Enhance Our Learning ### Question 1 *1 mark · MCQ* Which metal is commonly used to make food packaging materials as it is cheaper, and its thin sheets can be folded easily into any shape? - Aluminium - Copper - Iron - Gold **Solution** 1. Aluminium is a cheap metal that possesses high malleability, allowing it to be beaten into thin sheets easily. 2. Therefore, aluminium is commonly used for making food packaging materials like foil. **Answer:** (i) Aluminium > Common mistake: Confusing aluminium with iron or copper which are not used for thin food wraps due to cost or rigidity. ### Question 2 *1 mark · MCQ* Which of the following metal catches fire when it comes in contact with water? - Copper - Aluminium - Zinc - Sodium **Solution** 1. Sodium is a very reactive metal that reacts vigorously with oxygen and water, generating a lot of heat and catching fire. 2. Thus, sodium is stored in kerosene to prevent exposure to moisture and air. **Answer:** (iv) Sodium > Common mistake: Choosing copper or zinc, which do not react with water. ### Question 3 *1 mark · True or false* State with reason(s) whether the following statements are True [T] or False [F]. (i) Aluminium and copper are examples of non-metals used for making utensils and statues. [ ] (ii) Metals form oxides when combined with oxygen, the solution of which turns blue litmus paper to red. [ ] (iii) Oxygen is a non-metal essential for respiration. [ ] (iv) Copper vessels are used for boiling water because they are good conductors of electricity. [ ] **Part (i)** 1. Aluminium and copper are metals, not non-metals. Answer (i): False **Part (ii)** 1. Metal oxides are basic in nature and turn red litmus paper to blue. Answer (ii): False **Part (iii)** 1. Living beings breathe in oxygen, which is a non-metal essential for survival. Answer (iii): True **Part (iv)** 1. Copper vessels are used because they are good conductors of heat, not electricity. Answer (iv): False **Answer:** (i) False, (ii) False, (iii) True, (iv) False > Common mistake: Mixing up the colour change of litmus for metal oxides (red to blue) and non-metal oxides (blue to red). ### Question 4 *3 marks · Short answer* Why are only a few metals suitable for making jewellery? **Solution** 1. Gold and silver are highly lustrous, highly malleable, and ductile metals. 2. They are also very unreactive and do not corrode easily when exposed to air and moisture. 3. These unique properties make only a few metals like gold and silver suitable for making lasting jewellery. **Answer:** Only a few metals like gold and silver are suitable for jewellery because they have high lustre, high malleability, and resist corrosion. > Common mistake: Forgetting to mention resistance to corrosion and lustre. ### Question 5 *3 marks · Short answer* Match the uses of metals and non-metals given in Column I with the jumbled names of metals and non-metals given in Column II. Column I (i) Used in electrical wiring (ii) Most malleable and ductile (iii) Living organisms cannot survive without it. (iv) Plants grow healthy when fertilisers containing it are added to the soil. (v) Used in water purification Column II (a) E N X Y G O (b) N E C O H I R L (c) P E P O R C (d) T E N G O I N R (e) O G D L **Solution** 1. Unscramble Column II terms: (a) OXYGEN, (b) CHLORINE, (c) COPPER, (d) NITROGEN, (e) GOLD. 2. Match each use: (i) Copper, (ii) Gold, (iii) Oxygen, (iv) Nitrogen, (v) Chlorine. **Answer:** (i)-(c), (ii)-(e), (iii)-(a), (iv)-(d), (v)-(b) > Common mistake: Incorrectly unscrambling the jumbled element names. ### Question 6 *3 marks · Short answer* What happens when oxygen reacts with magnesium and sulfur. What are the main differences in the nature of products formed? **Solution** 1. Magnesium reacts with oxygen to form magnesium oxide, which is a metal oxide and basic in nature. 2. Sulfur reacts with oxygen to form sulfur dioxide, which dissolves in water to form sulfurous acid, a non-metal oxide that is acidic in nature. 3. The main difference is that metal oxides are basic in nature, whereas non-metal oxides are acidic in nature. **Answer:** Magnesium forms a basic oxide, while sulfur forms an acidic oxide. > Common mistake: Confusing the acidic nature of non-metal oxides with the basic nature of metal oxides. ### Question 7 *3 marks · Short answer* Complete the following flow chart: **Solution** 1. 1. The starting element reacting with air and heat to form ash is Magnesium ($\text{Mg}$). 2. 2. When water is added to magnesium oxide ash, it forms a basic solution which turns red litmus blue. 3. 3. Thus, the missing terms are: first box is Magnesium, second box is Water, third box is Magnesium oxide solution. **Answer:** The missing terms in the flow chart are Magnesium, Water, and Magnesium oxide solution. > Common mistake: Confusing magnesium oxide with a non-metal oxide. ### Question 8 *3 marks · Short answer* You are provided with the following materials. Discuss which material would be your choice to make a pan that is most suitable for boiling water and why? Iron copper sulfur coal plastic wood cardboard **Solution** 1. 1. Copper or iron would be the choice for making a pan suitable for boiling water. 2. 2. Metals are good conductors of heat, which allows heat from the burner to easily transfer to the water inside the pan. 3. 3. Non-metals like sulfur, coal, plastic, wood, and cardboard are poor conductors of heat and cannot transfer heat efficiently. **Answer:** Copper or iron is the choice because they are good conductors of heat. > Common mistake: Choosing a non-metal like wood or plastic which does not conduct heat. ### Question 9 *3 marks · Short answer* You are provided with three iron nails, each dipped in oil, water and vinegar. Which iron nail will not rust, and why? **Solution** 1. 1. The iron nail dipped in oil will not rust. 2. 2. Rusting of iron requires both air (oxygen) and water (moisture). 3. 3. The layer of oil cuts off the contact of the iron nail with air, preventing it from rusting. **Answer:** The iron nail dipped in oil will not rust because oil prevents contact with air. > Common mistake: Thinking oil contains water. ### Question 10 *3 marks · Short answer* How do the different properties of metals and non-metals determine their uses in everyday life? **Solution** 1. 1. Metals are malleable and ductile, making them suitable for sheets, utensils, and wires. 2. 2. Metals are good conductors of heat and electricity, making them ideal for cooking vessels and electrical wiring. 3. 3. Non-metals are essential for life and daily use, such as oxygen for breathing and carbon as a building block of all life forms. **Answer:** Malleability, ductility, and conductivity determine metal uses, while biological and chemical properties determine non-metal uses. > Common mistake: Forgetting to mention non-metal properties and uses. ### Question 11 *3 marks · Short answer* One of the methods of protecting iron from getting rusted is to put a thin coating of zinc metal over it. Since sulfur does not react with water, can it be used for this purpose? Justify your answer. **Solution** 1. 1. No, sulfur cannot be used for coating iron to prevent rusting. 2. 2. Sulfur is a non-metal which is brittle, soft, and non-malleable, so it cannot be beaten into a protective thin layer like zinc. 3. 3. Protection of iron requires a metal like zinc which provides a strong, durable protective layer. **Answer:** No, sulfur cannot be used because it is brittle and lacks malleability to form a protective coating. > Common mistake: Assuming any substance that does not react with water can be used as a coating. ### Question 12 *3 marks · Short answer* An ironsmith heats iron before making tools. Why is heating necessary in this process? **Solution** 1. 1. An ironsmith heats an iron block in the furnace until it becomes red hot before beating it. 2. 2. Heating makes the iron softer and more malleable, allowing it to be easily shaped into tools like axes and spades using a hammer. 3. 3. Beating cold iron is difficult and can cause it to break or crack. **Answer:** Heating makes iron softer and more malleable so it can be easily shaped into tools. > Common mistake: Stating that heating melts the iron completely. ## Frequently asked questions ### How many questions are there in NCERT Solutions for Class 7 Science Chapter 4 The World of Metals and Non-metals? The Let Us Enhance Our Learning section has 12 questions in total. You can find step-by-step solutions for all of them in SwaVid's free PDF available on this page only. ### Which topics do the questions cover in this Class 7 Science chapter? The questions cover concepts such as jewellery metals, malleability of metals, oxides of metals and non-metals, and general properties of elements. Other topics include reactivity of metals with water, uses of elements, material choice for cooking pans based on heat conduction, and conditions for rusting of iron. ### What are the different types of questions asked in this chapter? The exercises include multiple-choice questions, short answer questions, and true or false questions. SwaVid provides detailed solutions for each type on this page to help students prepare thoroughly. ### How should I write answers to score full marks in Class 7 Science exams? To score full marks, structure your answers by defining key scientific terms first and then explaining the underlying concept clearly. Refer to SwaVid's free PDF solutions on this page to learn the correct step-by-step presentation method. ### Is the free PDF for this chapter based on the latest syllabus? Yes, the solutions follow the new NCERT book based on the NCF 2023 for the 2026-27 session. You can access SwaVid's free PDF and complete chapter breakdown on this page only. ## Related pages - [Class 7 Science chapters](https://www.swavid.com/science/class/7) Solutions written by SwaVid, a personal AI tutor for Class 6 to 10 Maths and Science. Practise this chapter free: https://www.swavid.com/start/student