Group 6 Elements of the periodic table
Here’s the diagrammatic infographic of Group 6 elements — Chromium (Cr), Molybdenum (Mo), and Tungsten (W) — along with their major applications.
https://copilot.microsoft.com/th/id/BCO.0dc17771-7cdb-48ef-bc13-9dd5474661fd.png
⚛️ Group 6 Overview
- Members: Chromium (Cr), Molybdenum (Mo), Tungsten (W)
- Position: 6th group of the periodic table (d-block)
- Valence Electrons: 1
- Nature: Transition metals known for their hardness, high melting points, and strength
- Common Oxidation States: +2, +3, +6
- Nickname: The Hard Metals
🔧 Applications by Element
| Element | Major Applications |
|---|---|
| Chromium (Cr) | Stainless steel, plating, pigments, coatings |
| Molybdenum (Mo) | Alloys, lubricants, aerospace, catalysts |
| Tungsten (W) | Cutting tools, lightbulbs, high-temperature equipment, electrodes |
🛠 Key Industrial Uses
- Steel Industry: Chromium and molybdenum in stainless and high-strength steels.
- Aerospace: Tungsten and molybdenum alloys in jet engines and spacecraft.
- Electronics: Tungsten in filaments and electrodes.
- Surface Coating: Chromium for corrosion and wear resistance.
- Catalysts: Molybdenum in chemical and petrochemical processes.
⚡ Fun Facts
- Tungsten has the highest melting point of all metals.
- Chromium gives rubies and emeralds their vibrant colors.
- Molybdenum is essential for plant nutrition and enzyme functions.
Would you like me to create a comparative infographic showing Groups 6–8 together to visualize how their strength and catalytic properties evolve across the transition series?
Group 6 of the periodic table consists of Chromium (Cr), Molybdenum (Mo), Tungsten (W), and Seaborgium (Sg). These transition metals share similar chemical properties due to their valence electron configuration (ns² (n-1)d⁴).
🔹 Group 6 Elements Overview
| Element | Symbol | Atomic Number | Key Properties | Common Uses |
|---|---|---|---|---|
| Chromium | Cr | 24 | Hard, corrosion-resistant, forms colorful compounds | Stainless steel, chrome plating, pigments |
| Molybdenum | Mo | 42 | High melting point, strong alloying agent | Steel alloys, catalysts, lubricants |
| Tungsten | W | 74 | Extremely high melting point (3422 °C), very dense | Light bulb filaments, cutting tools, military applications |
| Seaborgium | Sg | 106 | Synthetic, radioactive, short-lived | No practical uses; studied for research in nuclear chemistry |
🔹 Key Chemical Characteristics
- Valence configuration: ns² (n-1)d⁴
- Oxidation states: Commonly +6, but also +2, +3, +4 depending on the compound.
- Reactivity: They form stable oxides and complex compounds.
- Trend: As you move down the group, melting points and densities increase significantly.
🔹 Notable Facts
- Chromium (Cr): Essential trace element in human nutrition (helps regulate blood sugar).
- Molybdenum (Mo): Required in small amounts for enzymes in plants and animals.
- Tungsten (W): Has the highest melting point of all metals, making it vital for high-temperature applications.
- Seaborgium (Sg): Named after Glenn T. Seaborg, discovered in 1974; exists only in laboratories.
🔹 Practical Importance
- Industrial relevance: Chromium and tungsten are critical for manufacturing durable alloys.
- Biological role: Molybdenum is essential for enzyme function in living organisms.
- Scientific research: Seaborgium expands our understanding of heavy synthetic elements, though it has no commercial use.
✅ In short: Group 6 elements are transition metals known for their strength, high melting points, and ability to form alloys. Chromium, molybdenum, and tungsten are widely used in industry, while seaborgium is purely of scientific interest.
Group 6 elements (Chromium, Molybdenum, Tungsten, and Seaborgium) are transition metals with high melting points, strong metallic bonding, and dense structures. Their physical properties show a clear trend: increasing melting point, density, and hardness as you move down the group.
🔹 Physical Properties of Group 6 Elements
| Property | Chromium (Cr) | Molybdenum (Mo) | Tungsten (W) | Seaborgium (Sg) |
|---|---|---|---|---|
| Atomic Number | 24 | 42 | 74 | 106 |
| Appearance | Silvery, hard metal | Silvery-gray, metallic | Steel-gray, very dense | Unknown (synthetic, short-lived) |
| Density | 7.19 g/cm³ | 10.28 g/cm³ | 19.25 g/cm³ | Estimated ~35–40 g/cm³ |
| Melting Point | 1907 °C | 2623 °C | 3422 °C (highest of all metals) | Unknown (predicted very high) |
| Boiling Point | 2671 °C | 4639 °C | 5555 °C | Unknown |
| Hardness | Very hard, brittle | Hard, strong | Extremely hard | Unknown |
| Electrical Conductivity | Good conductor | Good conductor | Good conductor | Unknown |
🔹 Trends Down the Group
- Density increases: Chromium is relatively light, while tungsten is extremely dense.
- Melting/boiling points rise: Tungsten holds the record for the highest melting point among all metals.
- Hardness strengthens: All are hard, but tungsten is exceptionally tough, used in cutting tools and armor.
- Metallic bonding becomes stronger due to more delocalized d-electrons.
🔹 Notable Physical Highlights
- Chromium (Cr): Hard, brittle, resists corrosion; used in stainless steel and plating.
- Molybdenum (Mo): High melting point, retains strength at high temperatures; used in alloys.
- Tungsten (W): Extremely dense and heat-resistant; used in filaments, military armor, and aerospace.
- Seaborgium (Sg): Synthetic, radioactive, exists only for seconds; physical properties are predicted but not experimentally confirmed.
🔹 Practical Importance
- Industrial use: Chromium and tungsten are vital for durable alloys.
- High-temperature applications: Tungsten’s unmatched melting point makes it irreplaceable in aerospace and defense.
- Scientific research: Seaborgium is studied for nuclear chemistry, not practical use.
✅ In summary: Group 6 elements are characterized by high melting points, hardness, and density, with tungsten standing out as the most extreme example. Seaborgium remains largely theoretical due to its instability.
Group 6 elements (Chromium, Molybdenum, Tungsten, and Seaborgium) are transition metals that commonly exhibit high oxidation states, form stable oxides, and show strong tendencies to create complex compounds. Their chemistry is dominated by the +6 oxidation state, though lower states (+2, +3, +4) are also observed.
🔹 Chemical Properties of Group 6 Elements
| Property | Chromium (Cr) | Molybdenum (Mo) | Tungsten (W) | Seaborgium (Sg) |
|---|---|---|---|---|
| Common Oxidation States | +2, +3, +6 | +2, +3, +4, +6 | +2, +4, +6 | Predicted +6 |
| Stable Oxides | Cr₂O₃, CrO₃ | MoO₂, MoO₃ | WO₂, WO₃ | SgO₃ (predicted) |
| Acid-Base Nature of Oxides | Amphoteric (Cr₂O₃), acidic (CrO₃) | Amphoteric | Amphoteric | Unknown |
| Halides | CrCl₂, CrCl₃, CrF₆ | MoCl₅, MoF₆ | WF₆ (volatile, used in semiconductor industry) | Predicted hexahalides |
| Complex Formation | Strong tendency to form coordination complexes | Forms stable complexes with ligands | Forms stable complexes, especially fluorides | Expected similar behavior |
| Reactivity | Resistant to corrosion, forms passivating oxide layer | Resistant to oxidation, reacts at high temperatures | Very resistant, reacts only at extreme conditions | Unknown, short-lived |
🔹 Key Chemical Characteristics
Oxidation states:
- Chromium shows a wide range, with +6 compounds (chromates, dichromates) being strong oxidizing agents.
- Molybdenum and tungsten favor +6 oxidation states in oxides and halides.
- Seaborgium is predicted to behave like tungsten, with stable +6 compounds.
Oxides:
- Chromium forms Cr₂O₃ (green, amphoteric) and CrO₃ (red, acidic, strong oxidizer).
- Molybdenum and tungsten form trioxides (MoO₃, WO₃), which are amphoteric and used in catalysts.
Halides:
- Tungsten hexafluoride (WF₆) is a volatile compound widely used in semiconductor manufacturing.
- Chromium and molybdenum halides are less volatile but form stable complexes.
Complexes:
- All Group 6 elements form strong coordination complexes with ligands like oxygen, nitrogen, and halides.
- Chromium complexes are colorful (basis of pigments).
- Molybdenum and tungsten complexes are important in catalysis.
🔹 Trends Down the Group
- Stability of +6 oxidation state increases from Cr → Mo → W.
- Volatility of halides increases (WF₆ is gaseous at room temperature).
- Resistance to oxidation increases down the group (tungsten is extremely resistant).
- Complex formation remains strong throughout, with heavier elements forming more stable complexes.
🔹 Practical Importance
- Chromium: Chromates/dichromates used in pigments, tanning, and as oxidizing agents.
- Molybdenum: Catalysts in petroleum refining, essential trace element in enzymes.
- Tungsten: Stable oxides and halides used in electronics and high-temperature applications.
- Seaborgium: No practical use; studied for theoretical chemistry.
✅ In summary: Group 6 elements are chemically versatile, dominated by the +6 oxidation state, forming stable oxides and halides. Chromium is notable for its colorful compounds, molybdenum and tungsten for their catalytic and industrial roles, and seaborgium for theoretical interest.
Here’s a clear overview of the practical uses of Group 6 elements (Chromium, Molybdenum, Tungsten, Seaborgium):
🔹 Chromium (Cr)
- Stainless steel production – improves corrosion resistance and hardness.
- Electroplating (“chrome plating”) – gives a shiny, protective finish to metals.
- Pigments – chromium compounds produce vivid colors (green, red, yellow).
- Leather tanning – chromium salts are used in the tanning process.
- Refractories – chromium oxide is used in high-temperature bricks and ceramics.
🔹 Molybdenum (Mo)
- Steel alloys – increases strength, toughness, and resistance to heat/corrosion.
- Catalysts – used in petroleum refining and chemical industries.
- Lubricants – molybdenum disulfide (MoS₂) is a solid lubricant for extreme conditions.
- Electronics – thin films in semiconductors and electrical contacts.
- Biological role – essential trace element in enzymes for plants and animals.
🔹 Tungsten (W)
- Filaments – used in incandescent light bulbs due to its very high melting point.
- Cutting tools & drills – tungsten carbide is extremely hard and durable.
- Military applications – armor-piercing projectiles and heavy alloys.
- Aerospace – high-temperature resistant components.
- Electronics – used in X-ray tubes, electrodes, and semiconductor processes.
🔹 Seaborgium (Sg)
- No practical uses – it is synthetic, highly radioactive, and exists only for seconds.
- Scientific research only – studied to understand the chemistry of superheavy elements.
🔹 Summary of Practical Importance
- Chromium → corrosion resistance, plating, pigments.
- Molybdenum → alloys, catalysts, lubricants.
- Tungsten → extreme heat resistance, tools, electronics, defense.
- Seaborgium → purely research interest.
✅ In short: Group 6 elements are indispensable in industry and technology, especially for alloys, high-temperature applications, and catalysts. Tungsten stands out for its unmatched melting point, while chromium is vital for stainless steel, and molybdenum for catalytic and alloying roles. Seaborgium remains a laboratory curiosity.
Part 1
- Lesson Summary
- Key Learning Points
- Glossary of Important Terms
- Multiple Choice Questions (with answers)
- Fill in the Blanks (with answers)
- True or False (with answers)
- Match the Following (with answers)
Part 2
8. One-word Questions & Answers
9. One-sentence Questions & Answers
10. Two-sentence Short Answer Questions
11. Descriptive Questions & Answers
12. Explanatory Questions & Answers
Part 3
13. Rank the Order of Importance Activities
14. Analytical/Critical Thinking Questions & Model Answers
15. HOTS (Higher Order Thinking Skills) Questions
16. Case Study-based Questions
17. Value-based Questions
18. Discussion Questions
19. Classroom Activities
20. Revision Worksheet
21. Complete Answer Key
This approach will allow me to provide a thorough, high-quality lesson resource without omitting any sections.
Part 1
1. Lesson Summary
Group 6 of the periodic table consists of Chromium (Cr), Molybdenum (Mo), Tungsten (W), and Seaborgium (Sg). These are transition metals known for their hardness, strength, high melting points, and corrosion resistance.
Chromium is widely used in stainless steel, electroplating, and pigments. Molybdenum strengthens steel alloys and acts as an important catalyst in the petroleum industry. Tungsten has the highest melting point of all metals and is used in cutting tools, aerospace components, and electrical equipment. Seaborgium is a synthetic radioactive element with no commercial applications and is mainly used for scientific research.
Group 6 elements commonly exhibit oxidation states of +2, +3, and +6. They form stable oxides, halides, and coordination compounds. Their importance in engineering, manufacturing, electronics, aerospace, and chemistry makes them indispensable modern industrial materials.
2. Key Learning Points
- Group 6 belongs to the d-block transition metals.
- Members are Chromium, Molybdenum, Tungsten, and Seaborgium.
- These metals are hard, dense, and strong.
- They possess very high melting points.
- Tungsten has the highest melting point among all metals.
- Chromium provides corrosion resistance.
- Molybdenum improves the strength of steel.
- Tungsten is used where very high temperatures are involved.
- Seaborgium is synthetic and radioactive.
- The most common oxidation state is +6.
- These elements form stable oxides and halides.
- Chromium compounds are often brightly colored.
- Molybdenum compounds are important catalysts.
- Tungsten carbide is one of the hardest engineering materials.
- Group 6 metals are essential in modern industries.
3. Glossary of Important Terms
| Term | Meaning |
|---|---|
| Transition Metal | Metal belonging to the d-block of the periodic table |
| Alloy | Mixture of metals to improve properties |
| Oxidation State | Charge an atom has after losing or gaining electrons |
| Catalyst | Substance that speeds up a chemical reaction without being consumed |
| Corrosion | Gradual destruction of metals by chemical reactions |
| Electroplating | Coating one metal with another using electricity |
| Pigment | Substance that provides colour |
| Refractory Material | Material resistant to very high temperatures |
| Semiconductor | Material with electrical conductivity between conductor and insulator |
| Coordination Compound | Compound containing a central metal ion bonded to ligands |
| Amphoteric Oxide | Oxide reacting with both acids and bases |
| Density | Mass per unit volume |
| Halide | Compound containing a halogen element |
| Filament | Thin wire that glows when heated electrically |
| Synthetic Element | Artificially produced element |
4. Multiple Choice Questions
Choose the correct answer.
- Group 6 belongs to the ______ block.
a) s
b) p
c) d
d) f
Answer: c) d
- Which element has the highest melting point among all metals?
a) Chromium
b) Iron
c) Tungsten
d) Copper
Answer: c) Tungsten
- Which element is mainly used in stainless steel?
a) Sodium
b) Chromium
c) Helium
d) Neon
Answer: b) Chromium
- Which Group 6 element is synthetic?
a) Chromium
b) Tungsten
c) Seaborgium
d) Molybdenum
Answer: c) Seaborgium
- Molybdenum is commonly used as a ______.
a) Fuel
b) Catalyst
c) Fertilizer
d) Gas
Answer: b) Catalyst
- Tungsten carbide is mainly used for
a) Paper
b) Cutting tools
c) Glass
d) Paint
Answer: b) Cutting tools
- Chromium compounds are widely used as
a) Pigments
b) Sugars
c) Medicines
d) Plastics
Answer: a) Pigments
- The most common oxidation state of Group 6 elements is
a) +1
b) +2
c) +6
d) –2
Answer: c) +6
- Seaborgium is mainly used for
a) Construction
b) Scientific research
c) Electronics
d) Agriculture
Answer: b) Scientific research
- Group 6 elements are known for their
a) Softness
b) Low melting point
c) Hardness and strength
d) Bright smell
Answer: c) Hardness and strength
5. Fill in the Blanks
- Chromium is used to make __________ steel.
Answer: stainless - Tungsten has the highest __________ point among all metals.
Answer: melting - Molybdenum is widely used in __________.
Answer: alloys - Seaborgium is a __________ element.
Answer: synthetic - Chromium provides excellent __________ resistance.
Answer: corrosion - Tungsten carbide is extremely __________.
Answer: hard - Group 6 elements belong to the __________ block.
Answer: d - Chromium is used in __________ plating.
Answer: chrome - Molybdenum is an important __________ in industries.
Answer: catalyst - Group 6 elements are __________ metals.
Answer: transition
6. True or False
- Chromium is used in stainless steel. True
- Tungsten has the lowest melting point. False
- Seaborgium is naturally abundant. False
- Molybdenum improves the strength of steel. True
- Group 6 elements belong to the d-block. True
- Chromium compounds can produce bright colours. True
- Tungsten is widely used in cutting tools. True
- Seaborgium has many commercial uses. False
- Group 6 elements are generally hard metals. True
- Molybdenum is used in catalysts. True
7. Match the Following
| Column A | Column B |
| Chromium | Stainless steel |
| Molybdenum | Catalyst |
| Tungsten | Highest melting point |
| Seaborgium | Scientific research |
| Chrome plating | Corrosion resistance |
| Tungsten carbide | Cutting tools |
| Pigments | Chromium compounds |
| Aerospace | Tungsten alloys |
| Lubricants | Molybdenum disulfide |
| Synthetic element | Seaborgium |
Answers
1 → Stainless steel
2 → Catalyst
3 → Highest melting point
4 → Scientific research
5 → Corrosion resistance
6 → Cutting tools
7 → Chromium compounds
8 → Tungsten alloys
9 → Molybdenum disulfide
10 → Seaborgium
Part 2
8. One-word Questions & Answers
- Which Group 6 element is used in stainless steel?
Answer: Chromium - Which Group 6 element has the highest melting point?
Answer: Tungsten - Which Group 6 element is synthetic?
Answer: Seaborgium - Which element is widely used as a catalyst?
Answer: Molybdenum - Which block does Group 6 belong to?
Answer: d-block - What is the common highest oxidation state of Group 6 elements?
Answer: +6 - Which element is used in chrome plating?
Answer: Chromium - Which element is essential for certain enzymes?
Answer: Molybdenum - Which element is used in light bulb filaments?
Answer: Tungsten - Which type of metals are Group 6 elements?
Answer: Transition metals
9. One-sentence Questions & Answers
What are the members of Group 6?
Answer: Group 6 consists of Chromium, Molybdenum, Tungsten, and Seaborgium.
Why is chromium added to steel?
Answer: Chromium is added to steel to improve its hardness and corrosion resistance.
Why is tungsten used in high-temperature equipment?
Answer: Tungsten is used because it has the highest melting point of all metals.
What is the importance of molybdenum?
Answer: Molybdenum strengthens alloys and acts as an industrial catalyst.
Why is seaborgium not used commercially?
Answer: Seaborgium is highly radioactive and exists only for a very short time.
What is the common oxidation state of Group 6 elements?
Answer: The most common oxidation state is +6.
Why are chromium compounds colorful?
Answer: Chromium compounds form brightly colored chemical compounds used as pigments.
What type of compounds do Group 6 elements commonly form?
Answer: They commonly form oxides, halides, and coordination compounds.
Which Group 6 element is important in aerospace?
Answer: Tungsten is important in aerospace because of its heat resistance.
Why are Group 6 elements important in industry?
Answer: They are strong, durable, and resistant to heat and corrosion.
10. Two-sentence Short Answer Questions
1. Why is chromium important in stainless steel?
Answer:
Chromium forms a protective oxide layer on steel. This layer prevents rusting and increases corrosion resistance.
2. Why is molybdenum added to alloys?
Answer:
Molybdenum increases the strength and toughness of metals. It also improves resistance to heat and corrosion.
3. Why is tungsten called a high-temperature metal?
Answer:
Tungsten has the highest melting point among all metals. It remains strong even at extremely high temperatures.
4. What is the significance of seaborgium?
Answer:
Seaborgium is a synthetic radioactive element. It is mainly used for scientific research.
5. What are the common oxidation states of Group 6 elements?
Answer:
Group 6 elements commonly show +2, +3, and +6 oxidation states. The +6 oxidation state is the most stable for many of them.
6. How are Group 6 elements useful in electronics?
Answer:
Tungsten is used in electrodes and semiconductor manufacturing. Molybdenum is also used in electronic thin films.
7. Why are Group 6 metals considered transition metals?
Answer:
They belong to the d-block of the periodic table. Their partially filled d-orbitals give them characteristic transition metal properties.
8. Why is molybdenum important for living organisms?
Answer:
Molybdenum is an essential trace element. It helps certain enzymes function properly in plants and animals.
9. Why is tungsten carbide widely used?
Answer:
Tungsten carbide is extremely hard and wear-resistant. It is widely used to manufacture cutting and drilling tools.
10. Why are Group 6 elements valuable in engineering?
Answer:
They possess excellent strength, hardness, and heat resistance. These properties make them suitable for demanding engineering applications.
11. Descriptive Questions & Answers
1. Describe the physical properties of Group 6 elements.
Answer:
Group 6 elements are hard, dense, and strong transition metals. Their melting points increase down the group, with tungsten having the highest melting point among all metals. They are also good conductors of electricity and possess excellent resistance to wear and heat.
2. Explain the chemical properties of Group 6 elements.
Answer:
Group 6 elements commonly exhibit oxidation states of +2, +3, and +6. They form stable oxides, halides, and coordination compounds. Chromium forms colorful compounds, while molybdenum and tungsten produce stable compounds widely used in industrial catalysis.
3. Explain the industrial importance of chromium.
Answer:
Chromium is widely used in stainless steel production because it improves hardness and corrosion resistance. It is also used in electroplating, pigments, leather tanning, and refractory materials.
4. Describe the applications of molybdenum.
Answer:
Molybdenum strengthens steel alloys used in construction and engineering. It serves as a catalyst in petroleum refining, acts as a lubricant in the form of molybdenum disulfide, and is used in electronics and biological enzyme systems.
5. Explain the importance of tungsten.
Answer:
Tungsten possesses exceptional hardness and the highest melting point among metals. It is used in cutting tools, aerospace components, electrical filaments, electrodes, X-ray tubes, and military equipment where extreme temperatures are encountered.
12. Explanatory Questions & Answers
1. Explain why Group 6 elements are called "Hard Metals."
Answer:
Group 6 elements possess outstanding hardness, strength, and resistance to wear. Their strong metallic bonding and dense atomic structures make them suitable for heavy industrial applications, earning them the nickname "Hard Metals."
2. Explain how the properties of Group 6 elements change down the group.
Answer:
As we move from chromium to tungsten, density and melting point generally increase. Heat resistance and stability also improve, making tungsten the most suitable element for extremely high-temperature applications.
3. Explain the importance of oxidation states in Group 6 chemistry.
Answer:
The ability to exist in different oxidation states enables Group 6 elements to form many useful compounds. Their +6 oxidation state is especially important in catalysts, pigments, corrosion-resistant materials, and industrial chemicals.
4. Explain why tungsten is important in modern technology.
Answer:
Tungsten combines exceptional hardness with the highest melting point of any metal. These properties make it indispensable for aerospace engineering, electronics, cutting tools, and other high-temperature technologies.
5. Explain why seaborgium is studied despite having no commercial use.
Answer:
Although seaborgium is short-lived and radioactive, scientists study it to understand the behavior of superheavy elements. This research expands knowledge of nuclear chemistry and the periodic table.
Part 3
13. Rank the Order of Importance Activities
Activity 1: Rank the Group 6 Elements by Industrial Importance
Arrange the following elements from highest to lowest industrial importance.
- Tungsten
- Chromium
- Molybdenum
- Seaborgium
Suggested Answer
- Chromium
- Tungsten
- Molybdenum
- Seaborgium
Activity 2: Rank the Following Applications According to Heat Resistance
- Stainless steel
- Jet engine components
- Cutting tools
- Light bulb filament
Suggested Answer
- Light bulb filament
- Jet engine components
- Cutting tools
- Stainless steel
Activity 3: Rank the Elements by Melting Point (Lowest → Highest)
- Chromium
- Molybdenum
- Tungsten
Answer
Chromium → Molybdenum → Tungsten
14. Analytical/Critical Thinking Questions & Model Answers
1. Why is chromium preferred for making stainless steel instead of ordinary iron?
Model Answer:
Chromium forms a protective oxide layer that prevents rusting. This greatly improves the durability and corrosion resistance of steel.
2. Why are tungsten tools suitable for cutting hard materials?
Model Answer:
Tungsten carbide is extremely hard and retains its strength even at very high temperatures, making it ideal for cutting and drilling.
3. Why is seaborgium not found in everyday products?
Model Answer:
Seaborgium is synthetic, highly radioactive, and exists only for a few seconds, making it unsuitable for commercial applications.
4. Why is molybdenum important in petroleum refining?
Model Answer:
Molybdenum compounds serve as efficient catalysts that increase the speed and efficiency of chemical reactions during refining.
5. What would happen if stainless steel contained no chromium?
Model Answer:
The steel would lose much of its corrosion resistance and would rust much more easily.
15. HOTS (Higher Order Thinking Skills) Questions
1. If tungsten had a much lower melting point, how would modern technology be affected?
Answer:
Many high-temperature applications such as aerospace components, cutting tools, and light bulb filaments would become less efficient or require alternative materials.
2. Why do scientists continue studying seaborgium even though it has no commercial use?
Answer:
Research on seaborgium helps scientists understand the behavior of superheavy elements and improves knowledge of nuclear chemistry and the periodic table.
3. Imagine a new alloy without molybdenum. What properties might be reduced?
Answer:
The alloy could have lower strength, reduced heat resistance, and poorer corrosion resistance.
4. Which Group 6 element would you choose for building a spacecraft engine? Give reasons.
Answer:
Tungsten would be the best choice because of its exceptional heat resistance, strength, and very high melting point.
5. Why do engineers often combine different Group 6 elements in alloys instead of using pure metals?
Answer:
Combining metals produces alloys with improved hardness, strength, durability, and resistance to heat and corrosion.
16. Case Study-based Questions
Case Study 1
A company is manufacturing kitchen utensils that should resist rust and remain shiny for many years.
Questions
- Which Group 6 element should be added?
- Why?
- What property makes it suitable?
Answers
- Chromium
- It prevents corrosion.
- It forms a protective oxide layer.
Case Study 2
An aerospace company needs a material for rocket engine parts that can withstand extremely high temperatures.
Questions
- Which element is most suitable?
- Why?
- Which property is most important?
Answers
- Tungsten
- It has the highest melting point among all metals.
- Excellent heat resistance.
17. Value-based Questions
1. Why should industries recycle valuable metals like chromium and tungsten?
Answer:
Recycling conserves natural resources, reduces mining, saves energy, and protects the environment.
2. Why should scientists handle radioactive elements carefully?
Answer:
Proper handling protects people and the environment from harmful radiation.
3. Why should engineers select materials responsibly?
Answer:
Choosing suitable materials improves safety, efficiency, durability, and sustainability.
4. How can learning chemistry benefit society?
Answer:
Chemistry helps develop stronger materials, cleaner technologies, better medicines, and sustainable industries.
18. Discussion Questions
- Why is tungsten called the king of high-temperature metals?
- How has chromium changed modern manufacturing?
- Should expensive metals always be recycled? Why?
- What industries depend most on Group 6 elements?
- Why are synthetic elements important for scientific research?
- How do catalysts improve industrial production?
- Why are alloys generally better than pure metals?
- Which Group 6 element do you think has the greatest impact on daily life? Explain.
19. Classroom Activities
Activity 1: Element Identification
Students identify the correct Group 6 element based on its properties or uses.
Activity 2: Application Chart
Prepare a chart showing:
- Element
- Property
- Industrial Use
- Everyday Example
Activity 3: Group Discussion
Topic:
"Which Group 6 element contributes the most to modern technology?"
Activity 4: Quiz Competition
Conduct a rapid-fire quiz using the MCQs and true/false statements from this lesson.
Activity 5: Research Assignment
Each student researches one Group 6 element and presents:
- Discovery
- Properties
- Uses
- Interesting facts
20. Revision Worksheet
A. Fill in the blanks
- Tungsten has the highest __________ point.
- Chromium prevents __________.
- Molybdenum is widely used in __________.
- Seaborgium is a __________ element.
- Group 6 belongs to the __________ block.
B. Answer in one sentence
- Why is chromium used in stainless steel?
- Why is tungsten used in cutting tools?
- What is the common oxidation state of Group 6 elements?
- What is the role of molybdenum in catalysts?
- Why is seaborgium studied?
C. Think and Answer
- Compare chromium and tungsten.
- Explain the importance of alloys.
- Describe the industrial uses of Group 6 elements.
- Explain why tungsten is valuable for aerospace engineering.
21. Complete Answer Key
Fill in the Blanks
- melting
- corrosion
- alloys
- synthetic
- d
One-sentence Answers
- Chromium improves corrosion resistance.
- Tungsten is extremely hard and heat-resistant.
- +6
- It speeds up chemical reactions.
- To study superheavy elements.
Think and Answer (Sample Points)
- Chromium resists corrosion; tungsten withstands extreme heat.
- Alloys are stronger, tougher, and more durable than pure metals.
- Group 6 elements are used in stainless steel, catalysts, cutting tools, aerospace, electronics, and research.
- Tungsten remains strong at very high temperatures, making it ideal for aerospace applications.
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