Glossary: Metals, Non-Metals, and Related Concepts
- Pure Substance
A material made up of only one kind of particles (atoms or molecules). Elements and compounds are examples of pure substances. - Element
A substance that cannot be broken down into simpler substances by chemical means. All atoms in an element are of the same type. - Compound
A substance formed when two or more elements chemically combine in a fixed proportion. Water (H₂O) is a compound. - Metal
A substance that is typically hard, shiny, malleable, ductile, sonorous, and a good conductor of heat and electricity. - Non-metal
A substance that generally lacks metallic properties; non-metals are brittle, dull, non-sonorous, and poor conductors. - Metalloid
Elements that show properties of both metals and non-metals. Example: Silicon (Si), Arsenic (As). - Malleability
The ability of a material to be hammered or rolled into thin sheets without breaking. - Ductility
The ability of a material to be drawn into thin wires. - Lustre
The shine or glow of a metal’s surface. Metals are generally lustrous. - Sonorosity
The ability of a substance to produce a ringing sound when struck. Metals are sonorous. - Tensile Strength
The ability of a material to withstand pulling forces without breaking. - Conductivity
The ability of a substance to transfer heat or electricity. It includes:- Thermal Conductivity – Heat transfer
- Electrical Conductivity – Current transfer
- Density
The mass per unit volume of a substance. Metals usually have high density. - Hardness
The resistance of a material to being scratched or deformed. - Occurrence
The natural presence of elements in the Earth’s crust or atmosphere, either in native form or as compounds. - Mineral
A naturally occurring inorganic substance found in the Earth’s crust. - Ore
A mineral from which one or more metals can be extracted profitably. - Metallurgy
The process of extracting and refining metals from their ores. - Concentration of Ore
The process of removing impurities from the ore to increase the percentage of metal. - Reduction
The process of obtaining a metal from its ore by removing oxygen or other elements. - Refining
The purification process of a crude metal to obtain its pure form. - Reactivity Series
A list of metals arranged in order of decreasing reactivity. - Displacement Reaction
A chemical reaction in which a more reactive element displaces a less reactive element from its compound. - Noble Metals
Metals that are chemically inert or least reactive. Example: Gold and Platinum. - Alloy
A homogeneous mixture of two or more elements, at least one of which is a metal. Example: Brass (Copper + Zinc). - Native State
The elemental or pure form in which less reactive metals exist naturally. - Alkali
A basic, water-soluble substance. Some metals react with alkalis to form salts. - Acid
A substance that releases hydrogen ions in water. Some metals and non-metals react with acids. - Carbonate
A compound containing the carbonate ion (CO₃²⁻), often found in metal ores. - Oxide
A compound formed when an element reacts with oxygen. - Sulphide
A compound of sulphur with a metal. - Brittle
A property of substances that break or shatter easily when stressed (common in non-metals). - Insoluble
A substance that does not dissolve in a solvent, such as water. - Corrosion
The gradual destruction of metals by chemical reaction with the environment, often forming oxides. - Tarnish
A thin layer of corrosion that forms on metals, dulling their appearance. - Carat (Karat)
A measure of the purity of gold, with 24 carat being pure gold.
Something To Know
Fill in the blanks.
- The property, due to which a metal piece can be hammered into thin sheets, is known as ________ .
Answer – malleability
- Bronze is an alloy of ________ and________.
Answer – copper and tin
- Gold is mixed with ________ and/or ________ to make it hard.
Answer – copper and/or silver
- ________ is the only non-metal to have a natural lustre.
Answer – Iodine
- ________ is a non-metal which catches fire in air.
Answer – Phosphorus
6.The only metal, which exists in the liquid state at room temperatures, is ________.
Answer – mercury
Match the following.
- Hardest substance (a) bromine
- Aluminium ore (b) graphite
- A non-metal, normally, existing in the liquid state (c) bauxite
- A good electrical conductor (d) diamond
- A metalloid (e) arsenic
Answer –
- Hardest substance (d) diamond
- Aluminium ore (c) bauxite
- A non-metal, normally existing in liquid state (a) bromine
- A good electrical conductor (non-metal) (b) graphite
- A metalloid (e) arsenic
Tick (✅) the correct option.
- The two most abundant metals, found in the earth’s crust, are—
aluminium and copper
aluminium and iron
iron and copper
iron and silver
Answer – aluminium and iron
- The metals, used in making the alloy ‘german silver’, are-
copper + zinc + tin
copper + zinc + nickel
copper + nickel + tin
copper + nickel + cobalt
Answer – copper + zinc + nickel
- When a metal reacts with oxygen, the resulting oxide of the metal
is a neutral oxide
turns blue litmus red
is a acidic oxide
is a basic oxide
Answer – is a basic oxide
- Out of the metals, gold, silver, copper and aluminium, the one, that is most ductile, is—
gold
silver
aluminium
copper
Answer – gold
- Two of the metals, that cannot be stored either in air, or under water, are— sodium and magnesium
magnesium and calcium
calcium and potassium
potassium and sodium
Answer – potassium and sodium
D. Answer the following questions in brief:
Answer the following questions in brief.
- Name (i) one metal and (ii) one non-metal which normally exists in the liquid state.
Answer – (i) Metal: Mercury
(ii) Non-metal: Bromine
- State the fraction of gold present in an 18-carat gold piece.
Answer – The fraction of gold in an 18 carat gold piece is 18/24 or 3/4, which is 75% gold.
- State the property of copper wires that makes them useful for electrical fittings.
Answer – Copper wires are good conductors of electricity and have high ductility, which makes them useful for electrical fittings.
- Define an alloy.
Answer – An alloy is a mixture of two or more metals, or a metal and a non-metal, usually combined to enhance properties like strength, durability, or resistance to corrosion.
- List any two uses of non-metals.
Answer – Oxygen: Used for respiration and combustion.
Sulfur: Used in the production of sulfuric acid, which is used in fertilizers.
E. Answer the following questions.
- Write the balanced chemical equations for the following reactions:
(a) sodium reacts with oxygen
Answer – Sodium reacts with oxygen
Reaction: Sodium reacts with oxygen to form sodium oxide.
Balanced chemical equation:
4Na+O2→2Na2O
Here, sodium (Na) reacts with oxygen (O₂) to form sodium oxide (Na₂O).
(b) aluminium reacts with dilute hydrochloric acid
Answer – Reaction: Aluminium reacts with hydrochloric acid to form aluminium chloride and hydrogen gas.
Balanced chemical equation:
2Al+6HCl→2AlCl3+3H2
Here, aluminium (Al) reacts with hydrochloric acid (HCl) to form aluminium chloride (AlCl₃) and hydrogen gas (H₂).
- Why are gold and platinum suitable for making jewellery?
Answer – Gold and platinum are suitable for making jewellery due to their high malleability and ductility, which allow them to be shaped easily into various designs. Additionally, both metals are non-reactive and do not tarnish or corrode easily, which ensures that the jewellery remains shiny and beautiful over time. Furthermore, gold and platinum are biologically inert, making them hypoallergenic and safe to wear. These properties make them ideal for creating long-lasting and durable pieces of jewellery.
- ‘Sodium and potassium is stored under kerosene.’ Give reason.
Answer – Reason: Sodium and potassium are highly reactive metals, especially with water. When these metals come into contact with water, they react vigorously, producing heat, hydrogen gas, and hydroxides, which can cause a fire or explosion. Since kerosene is a non-reactive liquid, it prevents these metals from coming into contact with moisture or air, thus safely storing them without the risk of unwanted reactions. Kerosene is used because it is inert and does not react with sodium or potassium.
- Why is bronze preferred over copper metal for making statues?
Answer – Reason: Bronze is an alloy made from copper and tin. It is preferred over pure copper for making statues due to several reasons:
Durability: Bronze is stronger and more durable than copper. It is less prone to corrosion and can withstand the effects of weathering and time, making it ideal for outdoor statues.
Malleability: Bronze is more malleable than pure copper, allowing for finer details to be created in sculptures.
Aesthetic appeal: Bronze has a beautiful color and sheen that enhances the appearance of statues.
Better Casting: Bronze has a lower melting point than pure copper, which makes it easier to cast into intricate shapes, providing better control in statue-making.
Value Based Question
The chemistry teacher, while teaching her students, explained to them the differences between ‘metals’ and ‘non-metals’. She told them that both of them react with the same gas-oxygen-but their resulting oxides are ‘opposite’ in nature.
She then went on to say that, in a somewhat similar way, we could use our stay in the school either-
(i) to gain knowledge, learn good manners and develop, and tone up, different skills, or
(ii) to indulge in idle gossip and other frivolous and irrelevant activities.
- State two of the ‘values’ that the teacher conveyed to her students.
Answer – Value 1: Utilizing time productively – The teacher emphasized that just as metals and non-metals react differently with oxygen to form opposite types of oxides, students should use their time at school wisely to gain knowledge, develop skills, and learn good manners.
Value 2: Choosing the right path in life – The teacher conveyed that one should avoid indulging in frivolous activities and instead focus on personal growth and constructive learning to lead a meaningful and purposeful life.
- Give one example each of the reaction of a (i) metal, (ii) non-metal, with oxygen to explain the ‘opposite nature’ of the oxides formed in the two cases.
Answer – Give one example each of the reaction of a (i) metal, (ii) non-metal, with oxygen to explain the ‘opposite nature’ of the oxides formed in the two cases.
(i) Metal reaction with oxygen:
Example: Sodium reacts with oxygen to form sodium oxide, which is basic in nature.
4Na+O2→2Na2O
The sodium oxide reacts with water to form sodium hydroxide (NaOH), a strong base.
(ii) Non-metal reaction with oxygen:
Example: Sulphur reacts with oxygen to form sulphur dioxide, which is acidic in nature.
S+O2→SO2
Sulphur dioxide dissolves in water to form sulphurous acid (H₂SO₃), an acid.
These reactions demonstrate the opposite nature of oxides: metals form basic oxides, while non-metals form acidic oxides.
- Let the students form two teams: M (Metals) and N (Non-metals); let the two teams form ‘pairs’ to explain the differences between ‘their’ properties.
Answer – Let the students form two teams: M (Metals) and N (Non-metals); let the two teams form ‘pairs’ to explain the differences between ‘their’ properties.
Team M (Metals): The students in this team will present the following properties of metals:
Lustrous (shine)
Good conductors of heat and electricity
Ductile (can be drawn into wires)
Malleable (can be hammered into sheets)
Form basic oxides (e.g., sodium oxide)
High melting and boiling points
Team N (Non-metals): The students in this team will present the following properties of non-metals:
Dull appearance (lack of shine)
Poor conductors of heat and electricity
Brittle (break easily when solid)
Form acidic oxides (e.g., sulphur dioxide)
Low melting and boiling points
Can be gases, liquids, or solids at room temperature
The pairs can then discuss these differences and explain how these properties are related to the type of oxide (acidic or basic) formed when the substance reacts with oxygen.
Something To Do
- Find out the names of places in India where mines of gold, copper and iron are located. Also, write the names of the places where major steel plants are located.
Answer – Gold Mines:
Kolar Gold Fields (Karnataka)
Hatti Gold Mines (Karnataka)
Ranthambore Gold Mines (Rajasthan)
Copper Mines:
Khetri Copper Complex (Rajasthan)
Singhbhum Copper Belt (Jharkhand)
Malanjkhand Copper Project (Madhya Pradesh)
Iron Ore Mines:
Bailadila Iron Ore Mines (Chhattisgarh)
Noamundi Iron Ore Mines (Jharkhand)
Donimalai Iron Ore Mines (Karnataka)
Major Steel Plants:
Tata Steel (Jamshedpur, Jharkhand)
Steel Authority of India Limited (SAIL) Plants (Bokaro, Jharkhand; Rourkela, Odisha)
Bhilai Steel Plant (Chhattisgarh)
Visakhapatnam Steel Plant (Andhra Pradesh)
- The study of extracting metals from their ores is called metallurgy. Centuries ago, India was far ahead in metallurgy. Refer to books in library and find out the history of metallurgy in India.
Answer – History of Metallurgy in India:
Ancient India was known for its advanced knowledge of metallurgy, which dates back to the Vedic period (1500-500 BCE) and the Indus Valley Civilization (3300–1300 BCE).
Iron Metallurgy: India was among the first to produce iron, and the Iron Pillar of Delhi (around 4th century CE) stands as a remarkable example of ancient Indian metallurgy. It has resisted rusting for over 1600 years, showcasing high skill in metallurgy.
Steel Production: India was famous for producing Wootz steel, a type of high-quality steel, during the Chola period (around the 2nd century BCE). This steel was known for its sharpness and strength and was exported to other parts of the world, including the Middle East and Europe.
Bronze Metallurgy: The Chola Dynasty was also known for its exquisite bronze sculptures, made through a process known as the lost-wax technique.
Copper and Silver: Ancient Indian civilizations had a deep understanding of copper, silver, and gold extraction and refinement, and the Harappan Civilization is believed to have excelled in metallurgy.
Modern Indian Metallurgy: The British Raj saw the establishment of large-scale industries such as the Tata Steel Plant in Jamshedpur, marking the advent of modern metallurgy in India.
- Make a list of five articles used at home and school, which are made up of metals or alloys. Write their composition in a tabular form.
Answer –
Article | Composition |
Aluminum Foil | Aluminum (Al) |
Penny (Coin) | Copper (Cu), Zinc (Zn) |
Pen | Plastic casing, Steel (for nib) |
School Bell | Bronze (Copper and Tin) |
Iron Nail | Iron (Fe) |
These are just a few common articles found in homes and schools. Each item contains metals or alloys with unique properties, such as corrosion resistance or high conductivity, making them suitable for specific uses.
Additional Questions and Answers
Short Questions and Answers
Question – What is an alloy?
Answer – An alloy is a mixture of two or more metals, or a metal and a non-metal, which are combined to improve the properties like strength, durability, or resistance to corrosion.
Question – Why are metals good conductors of electricity?
Answer – Metals are good conductors of electricity because they have free-moving electrons that allow electric current to flow easily through them.
Question – Which metal is known for being the best conductor of heat?
Answer – Silver is the best conductor of heat among metals.
Question – What happens when a non-metal reacts with oxygen?
Answer – When a non-metal reacts with oxygen, it forms an acidic oxide that can turn blue litmus paper red.
Question – Name the non-metal that is used to disinfect water.
Answer – Chlorine is a non-metal used to disinfect water.
Question – What is the main property that makes metals useful for electrical wiring?
Answer – Metals, especially copper, are good conductors of electricity due to their free-moving electrons, making them ideal for electrical wiring.
Question – Which is the lightest metal?
Answer – Lithium is the lightest metal.
Question – What is the importance of carbon in steel?
Answer – Carbon gives steel its hardness and strength. The amount of carbon in steel determines whether it will be soft or hard.
Question – What is the name of the process by which metals are extracted from their ores?
Answer – The process of extracting metals from their ores is called metallurgy.
Question – Name one metal and one non-metal that are used in the manufacturing of fertilizers.
Answer – Nitrogen (a non-metal) is used in fertilizers, and phosphorus (a non-metal) is also commonly used in fertilizers.
Long Questions and Answers
Question – Explain the differences between metals and non-metals.
Answer – Metals and non-metals differ in several properties:
Physical state: Metals are typically solid (except mercury), while non-metals are gases or solids.
Appearance: Metals have a shiny appearance (lustrous), while non-metals lack lustre.
Conductivity: Metals are good conductors of heat and electricity, whereas non-metals are poor conductors (except graphite).
Malleability and Ductility: Metals are malleable (can be hammered into thin sheets) and ductile (can be drawn into wires), whereas non-metals are brittle.
Oxides: Metals form basic oxides, while non-metals form acidic oxides.
Question – Discuss the use of alloys in daily life. Provide examples.
Answer – Alloys are commonly used because they combine the properties of different metals to make them more durable, resistant to corrosion, or provide other beneficial properties. For example:
Bronze (Copper and Tin) is used for making statues, coins, and musical instruments because of its durability and resistance to corrosion.
Brass (Copper and Zinc) is used in making household items like doorknobs, musical instruments, and in electrical fittings due to its resistance to tarnishing and corrosion.
Stainless Steel (Iron, Chromium, and Nickel) is used in kitchenware, surgical instruments, and construction because it resists rust and has a high strength-to-weight ratio.
Question – Why is iron often alloyed with other metals? Explain the benefits of this process.
Answer – Iron is often alloyed with other metals to improve its properties. Pure iron is soft and brittle, so alloying it with elements like carbon, chromium, nickel, and manganese gives it better strength, hardness, and resistance to corrosion. For example:
Steel: When iron is alloyed with carbon, it forms steel, which is much stronger and more durable than pure iron.
Stainless Steel: Alloying iron with chromium and nickel makes it resistant to rust and corrosion, making it ideal for applications like kitchen utensils, medical equipment, and construction.
Question – What are the physical and chemical properties of non-metals?
Answer – Non-metals have distinct physical and chemical properties:
Physical properties: Non-metals are usually not shiny (lack lustre), they are brittle in solid form (except graphite), and they are poor conductors of heat and electricity.
Chemical properties: Non-metals form acidic oxides when combined with oxygen. They can gain electrons easily and form negative ions (anions). Non-metals like chlorine and oxygen are reactive with metals, while noble gases like helium and neon are inert.
Question – Explain the process of rusting. Why is rust harmful? How can it be prevented?
Answer – Rusting is the process in which iron reacts with oxygen and moisture from the air to form iron oxide (Fe₂O₃), commonly known as rust. The process is as follows:
4Fe+3O2+6H2O→4Fe(OH)3 Rust weakens the metal, making it brittle and less durable.
Rusting can be prevented by:
Rust weakens the metal, making it brittle and less durable. Rusting can be prevented by:
Painting: Applying a layer of paint to keep moisture and air away from the metal.
Galvanization: Coating iron or steel with a thin layer of zinc to prevent rusting.
Using alloys: Alloying iron with other metals like chromium to create stainless steel, which resists rusting.
Question – What are the properties of metals that make them suitable for use in construction?
Answer – Metals, especially steel, are widely used in construction because of their:
Strength: Metals like steel and iron are strong and durable, making them ideal for structural frameworks and foundations.
Malleability and Ductility: Metals can be easily shaped and stretched without breaking, which is essential for creating beams, rods, and wires.
Corrosion Resistance: Alloys like stainless steel are resistant to corrosion, making them suitable for construction in harsh weather conditions.
Question – Describe the difference between a physical change and a chemical change, giving examples related to metals and non-metals.
Answer – A physical change is a change that does not alter the chemical composition of a substance, whereas a chemical change involves a transformation that changes the substance into a different material with different properties.
Physical change: Bending a metal wire (such as copper) is a physical change because the copper remains the same metal, just reshaped.
Chemical change: When iron rusts, it reacts with oxygen and water to form iron oxide, which is a chemical change because the original iron is transformed into a different substance.
Question – What are the differences between the properties of metals and non-metals based on their reactions with water?
Answer – Metals and non-metals react differently with water:
Metals: Some metals, like sodium and potassium, react vigorously with water, releasing hydrogen gas and forming hydroxides. For example, sodium reacts with water to form sodium hydroxide and hydrogen gas. 2Na+2H2O→2NaOH+H2
Non-metals: Non-metals generally do not react with water. However, non-metals like chlorine dissolve in water to form acidic solutions, like hydrochloric acid.
Question – Why is gold considered a precious metal?
Answer – Gold is considered a precious metal due to its:
Rarity: Gold is found in limited quantities in nature, making it rare and valuable.
Durability: It does not tarnish, corrode, or rust over time, making it ideal for use in jewellery and coins.
Malleability: Gold is highly malleable and ductile, meaning it can be shaped easily without breaking.
Cultural and Economic Significance: Gold has been used as a standard for currency and a symbol of wealth for centuries.