An alloy is a substance composed of two or more elements, where the primary element is a metal.
How is an alloy different from a compound?
An alloy is a mixture of metals or metals with non-metals, while a compound consists of chemically bonded elements in fixed proportions.
Why are alloys created?
Alloys are created to improve the properties of pure metals, such as increasing strength, hardness, and corrosion resistance.
What happens to the atomic structure of a metal when it is alloyed?
The regular arrangement of atoms is disrupted, making it harder for layers of atoms to slide past each other, increasing strength.
What is the primary metal in duralumin?
Aluminium is the primary metal in duralumin.
Which alloy is commonly used in making aircraft bodies?
Duralumin is used for aircraft bodies due to its strength and lightweight properties.
What are the two main elements in brass?
Brass is composed of approximately 70% copper and 30% zinc.
What is the main advantage of brass over pure copper?
Brass is stronger than pure copper and more corrosion-resistant.
Which alloy is primarily used for making medals and statues?
Bronze is used for making medals and statues.
What is the primary component of steel?
Steel is primarily composed of iron with a small amount of carbon (0.2% – 2%).
How does carbon affect the properties of steel?
Carbon strengthens steel by preventing layers of iron atoms from sliding easily, making it harder and stronger.
Why is stainless steel resistant to corrosion?
Stainless steel contains chromium, which forms a protective oxide layer that prevents rust.
Which alloy is used for surgical instruments?
Stainless steel is used for surgical instruments due to its corrosion resistance.
What is the main element in pewter?
Pewter is primarily composed of tin (95%).
Why are alloys harder than pure metals?
The presence of different-sized atoms disrupts the metal’s atomic arrangement, making it harder for layers to slide past each other.
What are the key properties of alloys?
Alloys are generally harder, stronger, more corrosion-resistant, and sometimes more visually appealing than pure metals.
Why is steel commonly used in construction?
Steel is used in construction because it is strong and malleable.
Which alloy is commonly used for decorative objects and tableware?
Pewter is used for decorative objects and tableware.
How do alloys improve the appearance of metals?
Alloys can enhance the aesthetic appeal by creating shinier and more attractive surfaces.
Which experiment demonstrates the corrosion resistance of stainless steel?
An experiment comparing the corrosion resistance of stainless steel and iron shows that stainless steel resists rust better due to its protective oxide layer.
Explanation Questions
Explain why alloying improves the strength of metals.
Alloying introduces atoms of different sizes into the metal structure, disrupting the regular arrangement and making it harder for layers to slide past each other, thus increasing strength.
Why is pure iron not commonly used in construction?
Pure iron is too soft and malleable for construction, so it is alloyed with carbon to form steel, which is much stronger.
How does adding chromium to steel improve its properties?
Chromium reacts with oxygen to form a protective oxide layer that prevents rusting, making stainless steel corrosion-resistant.
Explain why brass is preferred for musical instruments.
Brass is corrosion-resistant, has good acoustic properties, and can be easily shaped, making it ideal for musical instruments.
Why is duralumin used in aircraft manufacturing?
Duralumin is lightweight, strong, and resistant to corrosion, making it suitable for aircraft structures.
Describe how atomic structure affects the hardness of alloys.
The presence of different-sized atoms disrupts the orderly structure of pure metals, preventing atomic layers from sliding easily and increasing hardness.
Why is bronze preferred for statues and medals?
Bronze is harder, more durable, and has an attractive appearance, making it suitable for statues and medals.
How does the addition of tin affect pewter?
Tin makes pewter shiny, malleable, and resistant to corrosion, making it ideal for decorative objects.
What is the importance of alloying in everyday life?
Alloying improves the strength, durability, and appearance of metals, making them more useful for structural, industrial, and decorative applications.
Why is corrosion resistance an important property of alloys?
Corrosion resistance extends the lifespan of metals, making them more suitable for long-term use in various environments.