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

The correct answer is Magnesium.

Key Points

• Magnesium is higher in the reactivity series compared to Iron, Aluminium, and Zinc.
• When magnesium reacts with sulphuric acid, it displaces hydrogen gas rapidly due to its high reactivity.
• The reactivity series of metals places magnesium above zinc, iron, and aluminium, making it more reactive.
• Hydrogen gas bubbles will form at a faster rate when magnesium is used in the reaction with sulphuric acid.

Additional Information

• Reactivity Series: The reactivity series is a list of metals arranged in order of decreasing reactivity to displace hydrogen from acids and water.
• Hydrogen Displacement: Metals higher in the reactivity series can displace hydrogen gas from acids faster than those lower in the series.
• Magnesium (Mg): A lightweight, silvery metal that reacts vigorously with acids to produce hydrogen gas.
• Sulphuric Acid (H₂SO₄): A strong acid commonly used in chemical reactions to test the reactivity of metals.
• Safety Precautions: When performing reactions with acids, appropriate safety measures like wearing gloves and goggles should be taken to prevent harm.

Answer: Cu, Ag, Au.​Key Points

• Reactivity Series and Metal Extraction:

  • Metals at the bottom of the activity series are the least reactive.

  • These metals are often found in the free state, such as gold, silver, platinum, and copper.

  • Copper and silver are also found in combined states as their sulphide or oxide ores.

• Highly Reactive Metals:

  • Metals at the top of the activity series (K, Na, Ca, Mg, Al) are very reactive.

  • These metals are never found in nature as free elements.

• Moderately Reactive Metals:

  • Metals in the middle of the activity series (Zn, Fe, Pb) are moderately reactive.

  • These metals are found in the earth’s crust mainly as oxides, sulphides, or carbonates.

• Ores and Oxides:

  • Many metal ores are oxides because oxygen is a highly reactive and abundant element on Earth.

• Categories of Metals Based on Reactivity:

  • Metals of low reactivity

  • Metals of medium reactivity

  • Metals of high reactivity

• Extraction Techniques:

  • Different techniques are used for extracting metals in each category:

    • Reduction using carbon

    • Electrolysis

    • Found in native state

• Enrichment of Ores:

  • Ores mined from the earth often contain impurities like soil, sand, etc., called gangue.

  • Gangue must be removed before metal extraction.

The correct answer is Magnesium.

Key Points

• In the reactivity series, metals are arranged based on their ability to lose electrons and form positive ions.
• Magnesium is placed between aluminium and zinc in the reactivity series due to its chemical properties and reactivity.
• Magnesium is more reactive than aluminium because it loses electrons more easily to form a cation but is less reactive than zinc.
• The reactivity of a metal is determined by its tendency to participate in oxidation-reduction reactions.
• Magnesium is a highly reactive metal that reacts with oxygen to form magnesium oxide (MgO) and with acids to release hydrogen gas.
• It is widely used in applications such as alloys, fireworks, and medicines due to its reactivity and lightweight nature.
• The placement of magnesium in the series makes it an important reference point for understanding the behavior of metals in displacement reactions.

 Additional Information

• Iron
  • Iron is less reactive than magnesium and zinc, which is why it is placed lower in the reactivity series.
  • It is widely used in industries for the production of steel and alloys.
  • Iron reacts with oxygen in moist air to form rust (iron oxide), a process known as corrosion.
• Copper
  • Copper is a low-reactivity metal and is placed much lower in the reactivity series compared to magnesium.
  • It is an excellent conductor of electricity and is commonly used in electrical wiring and electronics.
  • Copper does not react with water or dilute acids under normal conditions.
• Carbon
  • Although carbon is not a metal, it plays a significant role in the reactivity series as a reference for the reduction of metal oxides.
  • It is used in the extraction of metals from their ores through the process of reduction.
  • Carbon is also an essential element in the form of graphite and diamond, which have unique physical properties.

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 Kerosene.

Key Points

• Sodium metal is highly reactive and can easily react with water or moisture in the air, producing hydrogen gas and heat, which may lead to explosions.
• To prevent such reactions, sodium is stored in kerosene, a non-reactive liquid that isolates the metal from air and water.
• Kerosene acts as a protective medium by creating a physical barrier, ensuring the safe storage of sodium metal.
• Other storage mediums like water, alcohol, and open air are unsuitable as they react with sodium, causing hazardous chemical reactions.
• Sodium's reactive nature makes it essential for laboratories and industries to follow strict safety protocols during storage and handling.

Additional Information

• Reactivity of Sodium:
  • Sodium is an alkali metal belonging to Group 1 of the periodic table, known for its high reactivity.
  • It reacts vigorously with water to produce sodium hydroxide (NaOH) and hydrogen gas (H₂), releasing significant heat.
  • Its reactivity increases when exposed to air due to oxidation, forming sodium oxide or sodium hydroxide.
• Properties of Kerosene:
  • Kerosene is a hydrocarbon liquid commonly used as a fuel and solvent.
  • It is non-reactive with sodium and other alkali metals, making it ideal for storing reactive substances.
  • Kerosene's low volatility and stable nature further ensure safe storage conditions for sodium.
• Storage and Handling of Reactive Metals:
  • Reactive metals like sodium, potassium, and lithium must be stored in inert or non-reactive substances.
  • Proper labeling, airtight containers, and isolation from flammable materials are critical for safety.
  • Emergency protocols should be in place to address accidental spills or reactions.
• Applications of Sodium:
  • Sodium is widely used in industries for the production of chemicals like sodium hydroxide and sodium carbonate.
  • It serves as a coolant in nuclear reactors and is used in the manufacture of synthetic rubber.
  • Sodium vapor lamps are employed for street lighting due to their high efficiency and bright light output.

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.