🧪 Chemistry · Topic 5 of 10
Start with the study notes on Metals & Non-metals (definitions, examples and a quick revision), then work through 60 practice questions, each with the correct answer and a clear explanation of why it is right. When you are ready, take this topic as an interactive quiz to test yourself.
Topic overview
Metals are elements that are usually shiny, strong and good conductors. Their typical properties are:
Remember: Metals conduct because they contain free electrons that can move through them.
Non-metals are usually dull, brittle and poor conductors. Solid non-metals break into powder when hammered.
Example: Sulphur, carbon, phosphorus, oxygen and nitrogen are non-metals.
Metal oxide → basic · Non-metal oxide → acidic
Example: Zinc + hydrochloric acid → zinc chloride + hydrogen.
The reactivity series lists metals from most reactive to least reactive.
Potassium > Sodium > Calcium > Magnesium > Aluminium > Zinc > Iron > Copper > Silver > Gold
A more reactive metal can displace a less reactive metal from its salt solution. A less reactive metal cannot.
Examples:
An alloy is a mixture of a metal with other metals, or with a non-metal. It is made to improve strength or stop corrosion.
Remember: Aluminium is quite reactive, but a thin, tough oxide layer forms on its surface and protects it from further corrosion.
Metalloids are elements with properties of both metals and non-metals.
Example: Silicon conducts electricity only partly (a semiconductor), so it is used to make computer chips and solar cells.
| Misconception | Correct understanding |
|---|---|
| All metals are hard solids. | Mercury is liquid; sodium and potassium are soft. |
| No non-metal conducts electricity. | Graphite, a form of carbon, conducts electricity. |
| Pencil “lead” is the metal lead. | Pencils contain graphite mixed with clay. |
| Metal oxides are acidic. | Metal oxides are basic; non-metal oxides are acidic. |
| Any metal can displace any other metal. | Only a more reactive metal can displace a less reactive one. |
Which metal is the best conductor of electricity?
Silver.
Why are sodium and potassium stored under kerosene?
They react violently with air and moisture.
Name a non-metal that conducts electricity.
Graphite.
Is sulphur dioxide acidic or basic?
Acidic: it is a non-metal oxide.
Can copper displace zinc from zinc sulphate?
No, because copper is less reactive than zinc.
What is brass made of?
Copper and zinc.
Why is nitrogen filled in chip packets?
It is unreactive, so it stops the oil in the chips from going bad.
Why is tungsten used in bulb filaments?
Its very high melting point lets it glow white-hot without melting.
Key takeaway: Metals are shiny, malleable conductors that form basic oxides; non-metals are mostly dull, brittle non-conductors that form acidic oxides. Remember the exceptions.
Notes written by Velnov for Class 6–8 students, following the topics of the NCERT science syllabus.
Q1. easy
Which of the following is a property of MOST metals?
Answer: A — They are shiny, hard, malleable and good conductors
Metals typically show lustre, hardness, malleability, ductility, sonority and good conduction of heat and electricity. Non-metals generally show the opposite properties.
Q2. easy
The shine seen on the surface of a freshly cut metal is called:
Answer: A — Metallic lustre
Metallic lustre is the characteristic shine of metals. Gold, silver and freshly cut sodium all show it, though many metals dull on exposure to air.
Q3. medium
The property by which metals can be beaten into thin SHEETS is called:
Answer: A — Malleability
Malleability lets metals like aluminium and gold be hammered into thin sheets - for example, aluminium foil used to wrap food.
Q4. medium
The property by which metals can be drawn into thin WIRES is called:
Answer: A — Ductility
Ductility allows metals like copper and aluminium to be drawn into wires. This is why electrical wiring is made from these metals.
Q5. medium
The property by which metals produce a ringing sound when struck is called:
Answer: A — Sonority
Sonorous metals ring when struck, which is why school bells, temple bells and cymbals are made of metal. Non-metals are not sonorous.
Q7. medium
Electrical wires are usually made of copper or aluminium because these metals are:
Answer: A — Good conductors of electricity and ductile
Copper and aluminium conduct electricity well and can be drawn into long thin wires. They are also reasonably cheap and resistant to corrosion.
Q10. medium
Sodium and potassium are stored under kerosene because:
Answer: A — They react violently with air and moisture, sometimes catching fire
These metals react vigorously with oxygen and water vapour in the air and can catch fire. Kerosene keeps air and moisture away from their surface.
Q13. medium
Which of these is a NON-METAL?
Answer: A — Sulphur
Sulphur is a brittle, dull yellow non-metal. Copper, zinc and aluminium are all metals.
Q14. medium
Non-metals are generally:
Answer: A — Dull, brittle and poor conductors of heat and electricity
Solid non-metals like sulphur and phosphorus break into pieces when hammered - they are brittle. They also lack lustre and do not conduct well.
Q16. medium
Which non-metal is essential for breathing and burning?
Answer: A — Oxygen
Oxygen supports respiration in living beings and combustion of fuels. It makes up about 21% of the air.
Q18. medium
Which non-metal is used in fertilisers and is important for plant growth?
Answer: A — Nitrogen
Nitrogen compounds such as urea and ammonium nitrate are essential fertilisers. Plants need nitrogen to make proteins.
Q20. medium
When a metal burns in air (oxygen), it forms:
Metal + Oxygen → Metal oxide (basic)Answer: A — A metal oxide, which is basic in nature
Metals combine with oxygen to give metal oxides. These dissolve in water to form bases, so metal oxides are described as basic oxides.
Q21. medium
When a non-metal burns in air (oxygen), it forms:
Non-metal + Oxygen → Non-metal oxide (acidic)Answer: A — A non-metal oxide, which is acidic in nature
Non-metals form oxides that dissolve in water to give acids. For example, sulphur dioxide dissolves to form sulphurous acid, so non-metal oxides are acidic.
Q23. medium
Metals react with dilute acids to produce:
Answer: A — A salt and hydrogen gas
Reactive metals displace hydrogen from acids: Zn + 2HCl → ZnCl2 + H2. The hydrogen released burns with a pop sound.
Q25. medium
Which metal reacts so vigorously with water that it catches fire?
Answer: A — Sodium
Sodium reacts violently with cold water, releasing hydrogen and enough heat to set it alight. Iron reacts only with steam, and copper and gold do not react with water at all.
Q28. medium
A more reactive metal can displace a less reactive metal from its salt solution. This is called:
Answer: A — A displacement reaction
For example, iron placed in copper sulphate solution displaces copper: Fe + CuSO4 → FeSO4 + Cu. The blue solution turns green and copper deposits on the iron.
Q30. medium
Which metal is used in making aeroplane bodies because it is light and strong?
Answer: A — Aluminium
Aluminium has a low density but good strength, especially when alloyed. It also resists corrosion, making it ideal for aircraft and vehicle bodies.
Q31. medium
Gold and silver are used for jewellery mainly because they:
Answer: A — Are shiny, malleable and do not corrode easily
Gold and silver are highly unreactive, so they keep their shine for years. They are also malleable and ductile, allowing intricate designs.
Q33. medium
Which metal is used to make cooking utensils because it conducts heat well and is cheap?
Answer: A — Aluminium
Aluminium is a good heat conductor, light, cheap and corrosion-resistant, making it popular for cooking vessels. Stainless steel and copper are also used.
Q35. medium
Brass is an alloy of:
Answer: A — Copper and zinc
Brass is made from copper and zinc. It is harder than copper, resists corrosion, and is used for utensils, locks and musical instruments.
Q36. medium
Bronze is an alloy of:
Answer: A — Copper and tin
Bronze is copper mixed with tin. It is harder and more durable than pure copper, and was historically used for tools, weapons and statues.
Q38. medium
Which metal is used inside dry cells as the outer casing and also to galvanise iron?
Answer: A — Zinc
Zinc forms the container and negative electrode of a dry cell, and is also coated on iron sheets during galvanisation to prevent rusting.
Q40. medium
Which non-metal is used in pencils?
Answer: A — Graphite
Despite the name 'pencil lead', pencils contain graphite mixed with clay - not the metal lead. Graphite is soft and leaves a mark on paper.
Q42. medium
Which non-metal is used to fill balloons because it is lighter than air and non-flammable?
Answer: A — Helium
Helium is lighter than air and does not burn, so it is safe for weather balloons and party balloons. Hydrogen is lighter still but dangerously flammable.
Q44. medium
Which of these pairs correctly matches a substance with its type?
Answer: A — Iron - metal; Sulphur - non-metal
Iron is a hard, shiny, sonorous, conducting metal. Sulphur is a dull, brittle, non-conducting yellow non-metal.
Q46. medium
Silicon is important in the electronics industry because it is:
Answer: A — A semiconductor - it conducts electricity partially
Silicon's conductivity lies between that of metals and non-metals and can be controlled precisely, which makes it the basis of computer chips and solar cells.
Q48. medium
Why are cooking vessel handles NOT made of metal?
Answer: A — Metals conduct heat well and would burn the hand
A metal handle would quickly become as hot as the pan. Wood and plastic are poor conductors (insulators), so they stay cool enough to hold.
Q50. medium
Which metal is used in thermometers (older type) because it expands uniformly on heating?
Answer: A — Mercury
Mercury expands evenly with temperature, does not stick to glass and is easy to see. Because it is toxic, digital and alcohol thermometers are now preferred.
Q52. medium
Which metal is used to make tin cans for food storage, coated over iron?
Answer: A — Tin
'Tin' cans are actually steel cans coated with a thin layer of tin. Tin does not react with food and protects the iron underneath from rusting.
Q54. medium
Nitrogen gas is filled in packets of chips because it:
Answer: A — Is unreactive and prevents the food from getting oxidised and spoiled
Oxygen would react with the oils in chips and turn them rancid. Nitrogen is chemically inactive, so it keeps the food fresh and also cushions the chips.
Q56. medium
Bromine is unusual because it is:
Answer: A — A non-metal that is liquid at room temperature
Bromine is the only non-metal that is liquid at room temperature - a reddish-brown, strong-smelling liquid. Mercury is the corresponding liquid metal.
Q58. medium
Which of these would you expect to conduct electricity?
Answer: A — A copper rod
Copper is a metal with free electrons and conducts electricity well. Sulphur, rubber and wood are insulators (graphite is the notable non-metal exception).
Q60. medium
Why is copper used at the base of many stainless steel cooking pans?
Answer: A — Copper conducts heat better, so the food heats evenly and quickly
Stainless steel does not conduct heat very well, so hot spots can form. A copper (or aluminium) base spreads the heat evenly across the pan while the steel surface stays easy to clean and rust-free.
Q6. hard
Which metal is the BEST conductor of electricity?
Answer: A — Silver
Silver is the best conductor of electricity, followed by copper. Copper is used for wiring instead of silver because it is far cheaper.
Q8. hard
Which metal is a LIQUID at room temperature?
Answer: A — Mercury
Mercury is the only metal that is liquid at ordinary room temperature. It is used in some thermometers and barometers, though it is toxic.
Q9. hard
Which metals are so SOFT that they can be cut with a knife?
Answer: A — Sodium and potassium
Sodium and potassium are exceptionally soft metals that can be cut easily with a knife. They are also so reactive that they are stored under kerosene.
Q11. hard
Which is the HARDEST naturally occurring substance, and it is a non-metal?
Answer: A — Diamond (a form of carbon)
Diamond is an allotrope of carbon and is the hardest known natural substance - an important exception to the rule that non-metals are soft.
Q12. hard
Which NON-METAL conducts electricity and is used in electrodes?
Answer: A — Graphite
Graphite, another form of carbon, conducts electricity because of its free electrons. It is used in dry cell electrodes and as pencil 'lead'.
Q15. hard
When a non-metal like sulphur is hammered, it:
Answer: A — Breaks into powder because it is brittle
Non-metals are brittle: they shatter rather than change shape. Malleability and ductility are properties of metals, not non-metals.
Q17. hard
Which non-metal is used to purify drinking water?
Answer: A — Chlorine
Chlorine kills bacteria and other germs in water, so it is added at water treatment plants and in swimming pools as a disinfectant.
Q19. hard
Which non-metal is used in crackers and matchsticks?
Answer: A — Phosphorus and sulphur
Red phosphorus is used on the striking surface of matchboxes, and sulphur is used in matchsticks, crackers and gunpowder because both ignite easily.
Q22. hard
Sulphur dioxide dissolved in water turns blue litmus red. This shows the solution is:
SO2 + H2O → H2SO3 (sulphurous acid)Answer: A — Acidic
SO2 + H2O → H2SO3 (sulphurous acid). Acids turn blue litmus red, confirming that non-metal oxides are acidic.
Q24. hard
Do non-metals generally react with dilute acids to release hydrogen?
Answer: A — No - non-metals do not displace hydrogen from acids
Non-metals cannot give away electrons to hydrogen ions, so they do not displace hydrogen from acids. This is a key difference from metals.
Q26. hard
Which metals do NOT react with water even at high temperatures?
Answer: A — Copper, silver and gold
Copper, silver and gold are among the least reactive metals and do not react with water or steam. This is why they are used for ornaments, utensils and coins.
Q27. hard
The list of metals arranged in order of decreasing reactivity is called the:
Answer: A — Reactivity series
In the reactivity series, potassium, sodium and calcium are most reactive, while gold and platinum are least reactive. A metal higher in the series can displace one lower down.
Q29. hard
Copper cannot displace zinc from zinc sulphate solution because:
Answer: A — Copper is LESS reactive than zinc
Displacement works only downward in the reactivity series. Since zinc is above copper, copper cannot push zinc out of its salt - no reaction takes place.
Q32. hard
Aluminium does not corrode easily because:
Answer: A — A thin protective layer of aluminium oxide forms on its surface
Aluminium is actually quite reactive, but the oxide layer that forms instantly on its surface is tough and sticks firmly, sealing the metal underneath from further attack.
Q34. hard
A mixture of two or more metals (or a metal with a non-metal) is called:
Answer: A — An alloy
Alloys are made to improve properties. Steel (iron + carbon), brass (copper + zinc) and bronze (copper + tin) are common alloys, stronger or more corrosion-resistant than the pure metals.
Q37. hard
Steel is an alloy of iron with:
Answer: A — A small amount of carbon
Adding a small percentage of carbon to iron makes steel, which is far stronger and harder than pure iron. Stainless steel additionally contains chromium and nickel.
Q39. hard
Which metal is used to make the filament of an electric bulb because of its very high melting point?
Answer: A — Tungsten
Tungsten has an extremely high melting point (about 3400 °C), so it glows white-hot without melting when current passes through it.
Q41. hard
Which non-metal is used as an antiseptic on wounds?
Answer: A — Iodine
Tincture of iodine, a solution of iodine in alcohol, is applied to cuts and wounds to kill germs. Iodine is also needed by the thyroid gland.
Q43. hard
Which of these best explains why metals are good conductors of electricity?
Answer: A — They contain free electrons that can move through the metal
In a metal, the outer electrons are loosely held and move freely throughout the structure. This 'sea' of mobile electrons carries electric current and heat.
Q45. hard
Elements that show properties of BOTH metals and non-metals are called:
Answer: A — Metalloids
Metalloids such as silicon, germanium, arsenic and boron have intermediate properties. Silicon, for instance, is used in semiconductors because it conducts only partly.
Q47. hard
Which of these statements about metal and non-metal oxides is CORRECT?
Answer: A — Metal oxides are basic; non-metal oxides are acidic
Metal oxides like magnesium oxide dissolve to form bases and turn red litmus blue. Non-metal oxides like sulphur dioxide dissolve to form acids and turn blue litmus red.
Q49. hard
Which reaction correctly shows a metal reacting with a base?
Answer: A — Aluminium with sodium hydroxide, releasing hydrogen gas
Most metals do not react with bases, but aluminium and zinc are exceptions - they react with strong bases like sodium hydroxide to release hydrogen gas.
Q51. hard
Which is the most reactive metal among these?
Answer: A — Potassium
Potassium sits at the very top of the reactivity series, reacting explosively with water. Gold is at the bottom and stays unreacted for centuries.
Q53. hard
Which non-metal exists as a diatomic gas that makes up about 78% of air?
Answer: A — Nitrogen
Nitrogen (N2) forms about 78% of the atmosphere. It is fairly unreactive, which is why it is used to fill food packets to prevent spoilage.
Q55. hard
Which statement about the physical state of elements is CORRECT?
Answer: A — Most metals are solid, but mercury is liquid; non-metals may be solid, liquid or gas
Mercury is a liquid metal; bromine is a liquid non-metal; sulphur and carbon are solid non-metals; oxygen and nitrogen are gaseous non-metals. Exceptions exist on both sides.
Q57. hard
Why are metals used to make bells and musical instruments?
Answer: A — They are sonorous and produce a ringing sound when struck
Sonority is the ability to produce a sustained ringing sound. Alloys like bronze and brass are especially sonorous, which is why bells and cymbals are made from them.
Q59. hard
Which overall statement about metals and non-metals is CORRECT?
Answer: A — Metals are lustrous, malleable, ductile, sonorous conductors that form basic oxides; non-metals are mostly dull, brittle non-conductors that form acidic oxides
This sums up the topic. Remember the exceptions too: mercury (liquid metal), sodium and potassium (soft metals), diamond (hard non-metal), graphite (conducting non-metal) and bromine (liquid non-metal).