Metal MCQ Quiz in मल्याळम - Objective Question with Answer for Metal - സൗജന്യ PDF ഡൗൺലോഡ് ചെയ്യുക

The correct answer is Both A and R are true, and R is the correct explanation of A.

Key Points

• Metals generally possess a lustrous appearance, meaning they are shiny, which is one of their defining physical properties.
• Metals are known to be excellent conductors of heat and electricity due to the presence of free electrons that move freely through the lattice structure.
• Non-metals, on the other hand, lack lustre and are typically poor conductors of heat and electricity because they do not have free electrons available for conduction.
• The Assertion (A) that "Metals generally have a lustrous appearance and are good conductors of heat and electricity" is true.
• The Reason (R) that "Non-metals lack lustre and are usually poor conductors of heat and electricity" is also true.
• Reason (R) provides a valid explanation for the behavior of metals mentioned in the assertion. The comparison between metals and non-metals helps to understand why metals exhibit these properties.
• The relationship between metals and non-metals is based on their atomic structure, which defines their distinct physical and chemical properties.
• Examples of metals include copper, silver, and gold, which are highly lustrous and conductive. Examples of non-metals include carbon, sulfur, and phosphorus, which are dull and non-conductive.

Additional Information

Properties of metal-

• high melting points.
• good conductors of electricity.
• good conductors of heat.
• high density.
• malleability
• ductility 

Properties of non-metal-

• non-metals are neither malleable nor ductile; they are brittle.

The correct answer is Zinc.Key Points

• Zinc is more reactive than copper.
• Zinc is more reactive than copper metal and so it can displace copper from copper sulphate solution.
• Zinc displaces the metals present below it in the series.

Additional Information

• Reactivity of an element decreases from top to bottom in the given reactivity series.
  • Potassium (K) 
  • Sodium (Na) 
  • Calcium (Ca)
  • Magnesium (Mg) 
  • Aluminium (Al) 
  • Zinc (Zn) 
  • Carbon (C) 
  • Iron (Fe) 
  • Lead (Pb) 
  • Hydrogen (H) 
  • Copper (Cu) 
  • Silver (Ag)
  • Gold (Au)
• Platinum is known as a noble metal due to its remarkable resistance to corrosion and oxidation. It is one of the least reactive metals, which means that it does not easily react with other elements or compounds under normal conditions. This property makes platinum highly valuable for use in a variety of applications, such as in electronics, jewelry, and catalytic converters in vehicles.

The correct answer is Alloy.

Key Points

• Steel is a type of alloy made primarily of iron and carbon.
• The carbon content in steel typically ranges from 0.02% to 2.14% by weight, depending on the grade.
• Alloys, like steel, are formed to enhance certain properties such as strength, ductility, and resistance to corrosion.
• Besides carbon, steel can also contain other elements like manganese, chromium, vanadium, and tungsten to achieve specific characteristics.
• Steel is widely used in construction, manufacturing, and other industries due to its versatility and mechanical properties.

Additional Information

• Alloy
  • An alloy is a mixture of two or more elements, where at least one element is a metal.
  • Alloys are designed to have properties that are different from those of their component elements.
  • Examples include brass (copper and zinc) and bronze (copper and tin).
• Suspension
  • A suspension is a heterogeneous mixture in which solid particles are dispersed in a liquid or gas but do not dissolve.
  • Examples include muddy water and flour in water.
• Solution
  • A solution is a homogeneous mixture of two or more substances where the solute is dissolved in the solvent.
  • Examples include saltwater and sugar in water.
• Colloid
  • A colloid is a mixture where very small particles of one substance are evenly distributed throughout another substance.
  • Examples include milk, mayonnaise, and gelatin.

The correct answer is all of these.

Key Points

• Industries are increasingly substituting traditional metals like tin, steel, and copper with modern materials like ceramics, high-strength glass fibers, and plastics.
• Ceramics are favored for their high temperature resistance, low thermal conductivity, and excellent wear resistance, making them suitable for a variety of industrial applications.
• High-strength glass fibers are used in composites due to their high tensile strength, lightweight, and corrosion resistance, often replacing metal parts in automotive and aerospace industries.
• Plastics are widely used due to their versatility, low cost, ease of manufacturing, and resistance to corrosion, making them suitable replacements in numerous applications.

Additional Information

• Ceramics
  • Ceramics are inorganic, non-metallic materials that are typically made from clay and other natural minerals.
  • They are used in various industries for their properties such as hardness, thermal stability, and resistance to chemical corrosion.
  • Common applications include tiles, bricks, and insulators.
• High-Strength Glass Fibers
  • Glass fibers are made from fine strands of silica-based glass.
  • They are used in reinforced plastics and composites, providing high strength and rigidity.
  • Applications include wind turbine blades, automotive components, and aerospace structures.
• Plastics
  • Plastics are synthetic materials made from polymers and are versatile in their applications.
  • They are used in packaging, construction, electronics, and numerous other sectors due to their lightweight and durability.
  • Common types of plastics include polyethylene, polypropylene, and polyvinyl chloride (PVC).

The correct answer is Gold and platinum.

Key Points

• Gold and platinum are found in their native state due to their low reactivity.
• They are part of the noble metals group, which resist oxidation and corrosion.
• Gold and platinum are often found in their elemental form in nature, not combined with other elements.
• These metals are less likely to form compounds with other elements, which is why they are found in pure form.
• Both metals have been used historically in coinage, jewelry, and industrial applications due to their stability and rarity.

Additional Information

• Reactivity Series of Metals
  • The reactivity series arranges metals in order of their reactivity from highest to lowest.
  • Metals higher in the series, like potassium and sodium, are more reactive and readily form compounds.
  • Metals lower in the series, like gold and platinum, are less reactive and often found in their native state.
  • The reactivity series helps predict how metals will react with acids, water, and other substances.
• Native State
  • A native state refers to metals found in nature in their pure, elemental form.
  • Metals like gold, silver, and platinum are typically found in their native state due to their resistance to corrosion and oxidation.
  • Finding metals in their native state was historically significant for early human societies, leading to the development of metallurgy.
• Noble Metals
  • Noble metals include gold, platinum, and other metals resistant to corrosion and oxidation.
  • They are called "noble" due to their stability and rarity.
  • Noble metals are used in various high-value applications, including electronics, jewelry, and catalytic converters.
• Industrial and Historical Significance
  • Gold and platinum have been valued throughout history for their beauty and rarity.
  • Both metals have significant industrial applications due to their conductive and catalytic properties.
  • Gold is widely used in electronics for its excellent conductivity and resistance to tarnish.
  • Platinum is crucial in the automotive industry for catalytic converters, reducing harmful emissions.

The correct answer is Gold.

Key Points

• Gold is one of the few metals found in its native or free state in the earth's crust.
• It is highly unreactive, which means it does not easily form compounds with other elements.
• Gold is often found in its elemental form in veins within rocks, alluvial deposits, and nuggets in riverbeds.
• Due to its scarcity and desirable properties, gold has been valued and used for coinage, jewelry, and other arts throughout recorded history.

Additional Information

• Native Metals
  • Native metals are metals that are found in their metallic form, either pure or as an alloy, in nature.
  • Examples include copper, silver, and platinum, in addition to gold.
• Reactivity Series
  • The reactivity series is a series of metals, arranged by their reactivity from highest to lowest.
  • Gold is at the bottom of this series, indicating its low reactivity.
• Gold Mining
  • Gold mining involves the extraction of gold from its ores or alluvial deposits in the earth.
  • Techniques include panning, sluicing, dredging, and the use of cyanide leaching.
• Uses of Gold
  • Apart from jewelry, gold is used in electronics and medical devices due to its excellent conductivity and biocompatibility.
  • Gold is also held in reserves by central banks as a store of value and a hedge against inflation.

The correct answer is Aluminium.

Key Points

• Aluminium reacts with steam to form aluminium oxide and hydrogen gas.
• It does not react with cold or hot water due to the formation of a protective oxide layer on its surface.
• The reaction of aluminium with steam is represented by the equation: 2Al + 3H₂O (steam) → Al₂O₃ + 3H₂.
• This property distinguishes aluminium from more reactive metals such as sodium and potassium, which react vigorously with cold water.
• Aluminium's reactivity with steam but not with liquid water is crucial in various industrial applications, including metallurgy and manufacturing.

Additional Information

• Reactivity Series of Metals
  • It is a series of metals arranged in order of their reactivity from highest to lowest.
  • It helps predict how metals will react with water, acids, and other substances.
  • Highly reactive metals like potassium and sodium react with cold water, while less reactive metals like aluminium react only with steam.
• Oxide Layer Formation
  • Aluminium forms a thin, protective oxide layer when exposed to air.
  • This layer prevents further reaction with water and air, making it corrosion-resistant.
  • This property is utilized in industries to prevent rusting and degradation of aluminium products.
• Hydrogen Gas Production
  • When metals react with water or steam, hydrogen gas is often produced.
  • Hydrogen gas is highly flammable and must be handled with care in industrial settings.
  • The production of hydrogen gas is an important factor in reactions involving metals and water.
• Industrial Applications
  • Aluminium's selective reactivity is exploited in processes like the extraction of aluminium from bauxite ore.
  • It is also used in manufacturing processes where controlled reactions are required.
  • Understanding metal reactivity is crucial for safe and efficient industrial operations.

The Correct answer is Potassium.

Key Points

• Potassium is known to be the most reactive metal in the reactivity series.
• It belongs to the alkali metals group in the periodic table, which is Group 1.
• Potassium reacts vigorously with water, producing hydrogen gas and heat, which can ignite the hydrogen.
• Its high reactivity is due to its single valence electron, which it can easily lose to form a positive ion.
• This metal must be stored in oil or an inert atmosphere to prevent it from reacting with moisture or oxygen in the air.
• Potassium is used in various applications, including fertilizers and as a critical element in biological processes.

 Additional Information

• Gold
  • Gold is a less reactive metal and is found in its native form in nature.
  • It is highly valued for its non-reactivity and is used extensively in jewelry and electronics due to its excellent conductivity.
• Zinc
  • Zinc is a moderately reactive metal.
  • It is commonly used for galvanization to protect iron and steel from corrosion.
• Sodium
  • Sodium is also highly reactive, similar to potassium, and is part of the alkali metals group.
  • It reacts vigorously with water and oxygen and is used in various industrial processes.

The correct answer is Ductility.

Key Points

• Ductility is the property of a material that allows it to be drawn into thin wires.
• This property is most commonly observed in metals such as gold, silver, copper, and aluminum.
• Gold is known to be one of the most ductile metals, capable of being drawn into very fine wires.
• The measure of ductility is typically expressed as a percentage of elongation or the reduction of area in a tensile test.
• Ductility is essential for manufacturing processes like wire drawing and tube making.

Additional Information

• Malleability
  • Malleability is the ability of a material to be hammered or rolled into thin sheets without breaking.
  • Like ductility, malleability is a property of metals, allowing them to be shaped and formed.
  • Gold and silver are also highly malleable, making them useful for various industrial and jewelry applications.
• Tensile Strength
  • Tensile strength is the maximum amount of tensile stress that a material can withstand before failure.
  • It is an important property for materials that are used in structures and machines.
  • High tensile strength materials are often also ductile, but this is not always the case.
• Brittleness
  • Brittleness is the tendency of a material to break or shatter without significant deformation when under stress.
  • Brittle materials, like glass, ceramics, and some polymers, have low ductility and malleability.
  • These materials are often used where high hardness and low deformability are required.
• Plasticity
  • Plasticity is the ability of a material to undergo permanent deformation without breaking.
  • This property is crucial for processes such as forging, molding, and stamping.
  • Metals and polymers typically exhibit high plasticity.

The correct answer is Sodium.

Key Points

• Sodium is a highly reactive metal that can spontaneously ignite when exposed to air due to its reaction with oxygen and moisture.
• It forms sodium oxide and sodium hydroxide when it reacts with oxygen and water vapor in the air, releasing heat.
• Because of its high reactivity, sodium is stored under oil or in an inert atmosphere to prevent accidental fires.
• In its pure form, sodium is a soft, silvery-white metal that is part of the alkali metal group in the periodic table.

Additional Information

• Reactivity Series of Metals
  • The reactivity series is a list of metals ranked by their reactivity, from highest to lowest.
  • Metals like potassium, sodium, lithium, and calcium are highly reactive and placed at the top of the series.
  • These metals react vigorously with water and air, releasing hydrogen gas and forming hydroxides.
• Alkali Metals
  • Alkali metals belong to Group 1 of the periodic table and include lithium, sodium, potassium, rubidium, cesium, and francium.
  • They are characterized by having one electron in their outermost shell, making them highly reactive.
  • Alkali metals react strongly with water to form alkaline hydroxides and hydrogen gas.
• Safety Precautions for Handling Sodium
  • Sodium should be handled with care, using gloves and protective eyewear to avoid contact with skin and eyes.
  • It should be stored in a non-reactive substance like mineral oil or kerosene to prevent exposure to air and moisture.
  • In case of a sodium fire, it should not be extinguished with water; instead, use a Class D fire extinguisher designed for metal fires.