The World of Metals and Non-metals — Mastery

Q1. Yashwant and Anandi visit a local ironsmith in their Rajasthan village to learn about a craft that works mainly with

• A. Wood and bamboo
• B. Cotton and jute
• C. Iron metal
• D. Stone and clay

Q2. According to Sudarshan uncle, which of the following are commonly made by the ironsmiths in his village?

• A. Flat pans (tawa), buckets (balti), tongs (chimta)
• B. Glass bangles and clay pots
• C. Cotton cloth and silk threads
• D. Plastic bottles and rubber slippers

Q3. Which of the following metals are so soft that they can be cut with a knife?

• A. Iron and copper
• B. Sodium and potassium
• C. Aluminium and zinc
• D. Gold and silver

Q4. When a block of wood is beaten with a hammer in Activity 4.1, it neither flattens into a sheet nor breaks into pieces. The chapter therefore concludes that wood is

• A. Malleable like copper
• B. Brittle like coal
• C. Neither malleable nor brittle
• D. A type of metal

Q5. The Iron Pillar of Delhi is approximately how tall and how heavy, according to the chapter?

• A. About 2 metres high and 500 kg
• B. About 4 metres high and 2000 kg
• C. About 8 metres high and more than 6000 kg
• D. About 20 metres high and 60000 kg

Q6. When a clean magnesium ribbon is ignited and allowed to burn, what is observed?

• A. It melts into a black liquid without burning
• B. It burns with a dazzling white flame, forming a white powder of magnesium oxide
• C. It produces blue sparks and turns into a green gas
• D. Nothing happens until water is added

Q7. A tea strainer is made by weaving thin metal wires together. The property of metals that enables the strainer to be made is

• A. Malleability — flattening into sheets
• B. Conduction of heat
• C. Ductility — being drawn into wires
• D. Lustre — having a shiny surface

Q8. Steel is described in the chapter as

• A. A pure metal element with no other component
• B. A mixture of metal (iron) and non-metal (carbon)
• C. A pure non-metal substance
• D. A mixture of two non-metals only

Q9. A child with a visual impairment uses a walking stick and tells her teacher, 'I can tell whether my stick hit wood or metal by the sound.' Which property of metals is she using?

• A. Malleability
• B. Conduction of electricity
• C. Sonority
• D. Corrosion resistance

Q10. In Activity 4.3, a metal spoon and a wooden spoon of the same size are dipped together in hot water. After a few minutes, students touch the upper ends. They observe that

• A. The wooden spoon is hotter at the top
• B. Both spoons are equally hot at the top
• C. The metal spoon is hotter at the top
• D. Both spoons become cooler than the water

Q11. Why does the chapter call rusting of iron a 'serious problem in our country'?

• A. Because rust is poisonous and pollutes drinking water
• B. Because every year an enormous amount of money is spent to replace or repair iron structures damaged due to rusting
• C. Because rust spreads as a disease to all living organisms
• D. Because rust is a non-metal and reduces oxygen in air

Q12. Galvanisation prevents iron from rusting by

• A. Heating the iron until rust burns off
• B. Mixing iron with carbon to make steel
• C. Applying a protective layer of zinc metal on iron
• D. Coating iron with a layer of sulfur powder

Q13. Anita notices that her grandmother's silver bowl, kept open for a long time, has developed a black coating. This black coating is an example of

• A. Corrosion of silver
• B. Rusting of silver
• C. Galvanisation of silver
• D. Sonority of silver

Q14. According to the 'Dive Deeper' note in this chapter, the total number of known elements is presently

• A. 88
• B. 100
• C. 108
• D. 118

Q15. When sulfur powder is added to water in a glass tumbler (Activity 4.8), the observation is

• A. Sulfur dissolves to form a basic solution
• B. Sulfur reacts vigorously and gives off hydrogen gas
• C. No reaction takes place between sulfur and water
• D. Sulfur turns into rust on contact with water

Q16. Yashwant and Anandi's village visit to Sudarshan uncle is presented in the chapter as the starting point for which kind of learning activity?

• A. A historical research project on Mughal architecture
• B. A botany survey of plants used by farmers
• C. A geometry project on the shapes of farming tools
• D. A school project on metals and the everyday objects made from them

Q17. A shopkeeper in Indore wraps hot parathas in a thin aluminium sheet for a customer. Which property of aluminium directly enables the sheet to be folded over the parathas?

• A. Sonority of aluminium
• B. Brittleness of aluminium
• C. Electrical conductivity of aluminium
• D. Malleability of aluminium

Q18. A Class 7 teacher in Jaipur is planning to introduce malleability. Which opening best links the property to India's metal heritage, as the chapter encourages?

• A. Start with a chemical equation for rust on the blackboard
• B. Show pictures of the Iron Pillar of Delhi and discuss how ancient Indian craftsmen worked metals into massive shapes by hammering, then move to Activity 4.1
• C. Begin by listing the names of all 118 elements
• D. Ask students to memorise the periodic table positions of all metals

Q19. Ravi observes a clinical thermometer at a Delhi pharmacy and sees a silvery liquid inside the glass tube. The liquid is most likely

• A. Mercury, a metal that is in liquid state at room temperature
• B. Liquid sodium kept under a glass cover
• C. Molten iron at room temperature
• D. A non-metal in liquid form like sulfur

Q20. When an electrician wires a house in Bhopal, he uses copper and aluminium wires for the electrical fittings. Which two properties of these metals together make them the natural choice?

• A. Sonority and brittleness
• B. Magnetism and corrosion-resistance
• C. Lustre and softness
• D. Ductility (they can be drawn into long wires) and good electrical conduction

Q21. Gold and silver bangles, necklaces and earrings are common ornaments in Indian households. The chapter links these ornaments to which two properties of these metals together?

• A. They are radioactive and conduct electricity
• B. They are sonorous and brittle
• C. They are basic non-metals and dissolve in water
• D. They are highly malleable (beaten into shapes) and ductile (drawn into thin strands for chains and threads)

Q22. A metal spoon and a metal coin are dropped on a hard floor; both produce a clear ringing sound. A piece of wood dropped from the same height produces only a dull thud. Which of the following statements about this difference is correct?

• A. Metals are sonorous and produce a ringing sound on striking; wood is not sonorous and gives a dull sound
• B. Wood is sonorous and metals are not
• C. Both metals and wood are equally sonorous; the difference is only of weight
• D. The difference is caused by the temperature of the floor, not the materials

Q23. Two spoons of the same size — one metal, one wooden — are kept in identical bowls of hot dal for the same time. A student touches the upper ends and reports that the metal spoon feels much hotter. The best scientific explanation is that

• A. The metal spoon absorbed more dal into itself than the wooden spoon
• B. The wooden spoon stayed cooler because it weighs less
• C. The dal is hotter near the metal spoon than near the wooden spoon
• D. Heat conducts easily along the metal spoon to its upper end, but wood is a poor conductor of heat, so its upper end stays cooler

Q24. Asha sees an electrician in Pune climb a wooden ladder to fix a streetlight, wearing rubber-soled shoes and using a screwdriver with a plastic handle. The single common property of wood, rubber and plastic that protects him is that they are

• A. Magnetic substances
• B. Good conductors of heat
• C. Hard and lustrous metals
• D. Poor conductors of electricity

Q25. In a tester-circuit experiment, the bulb does NOT glow when the circuit is completed using a piece of sulfur, a piece of coal, a piece of wood and a piece of stone. The common reason is that these materials are

• A. Poor conductors of electricity, so they do not let current pass and the bulb stays unlit
• B. Highly magnetic and absorb all the electricity from the bulb
• C. Heavier than metals and stop the current by their weight
• D. Different colours from metals, which is why electricity refuses to flow

Q26. Consider three statements about rusting of iron as discussed in the chapter: I. Only the presence of dry air is enough to rust iron. II. Both water and air must come in contact with iron together for rust to form. III. In a desert with very dry air, iron tools rust as quickly as they do in coastal Mumbai. Which is/are correct?

• A. I and II only
• B. I and III only
• C. All three
• D. II only

Q27. A student in Delhi asks why the 1600-year-old Iron Pillar of Delhi has barely rusted while modern iron gates rust within a few years. Which of the following best evaluates the situation, as the chapter encourages?

• A. The Iron Pillar is actually made of stone, not iron, so it cannot rust
• B. The Iron Pillar is not exposed to rain or air, so the comparison is meaningless
• C. Modern gates are coated with rust, which is why they look brown — they have not really rusted
• D. Ancient Indian metalworkers had advanced metallurgical skills, producing iron with a composition that resists corrosion despite long exposure to weather — a fact that highlights how rich India's old metal-craft tradition was

Q28. A Class 7 teacher in Bhopal shows students a brass lamp from Tanjore, a Dhokra horse from Chhattisgarh and a Bidri vase from Karnataka. Which chapter idea is the teacher most directly connecting these objects to?

• A. India has a rich and diverse tradition of metal art and metallurgy, drawing on the malleability of metals to shape everyday and ceremonial objects
• B. Brass and Dhokra art are made by burning sulfur in air
• C. Bidri vases are pure non-metals, similar to glass
• D. These objects are all made by rusting iron in different ways

Q29. Consider these two laboratory storage practices: I. Sodium is stored in kerosene. II. Phosphorus is stored under water. The chapter explains both by the same broad principle. What is it?

• A. Both substances are non-metals that dissolve in their storage liquid
• B. Both liquids cool the substances down to absolute zero
• C. Both substances make their storage liquid radioactive, which is why no one touches them
• D. Each substance is highly reactive with air (and, for sodium, also with water); the storage liquid in each case keeps the reactive partner away — kerosene shuts out both moisture and air, water shuts out air

Q30. A Class 7 student says, 'Iodine is a metal, so its solution is dabbed on cuts to give the wound a shiny coating.' The teacher wants to correct this with a single best response that aligns with the chapter. Which response is most accurate?

• A. Yes, iodine is a soft metal and that is exactly why it heals cuts
• B. Iodine is a metal but it is dabbed on cuts because it is sonorous
• C. Iodine is a metal that conducts electricity and uses the body's current to heal cuts
• D. Iodine is a non-metal, not a metal; its solution is applied on wounds as an antiseptic because it kills disease-causing microbes — the use is medicinal, not for shine