Metals and Alloys Quiz

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Questions and Answers

What defines an alloy?

A solid solution of gases under pressure.

A mixture of two or more different metals or a metal and another element. (correct)

A combination of one metal and a non-metal only.

An element combined with a polymer.

Which statement about metals is true?

All metals are non-reactive to air and water.

Metals typically have more than three electrons in their outermost shell.

All metals have a low thermal conductivity.

Most metals are good conductors of electricity due to free electrons. (correct)

What is a property of metals that contributes to rusting in iron?

All metals corrode at the same rate.

Metals lack malleability and ductility.

Metals are non-reactive and do not corrode.

Rusting occurs when iron reacts with oxygen in the presence of moisture. (correct)

Which of the following is NOT a main physical property of metals?

Brittleness Signup and view all the answers

How can rusting be prevented in metals?

By covering the surface of the metal. Signup and view all the answers

Which property of metals allows them to be shaped without breaking?

Malleability Signup and view all the answers

What property describes a metal's ability to return to its original shape when deformed?

Elasticity Signup and view all the answers

Which property allows metals to conduct heat or electricity?

Conductivity Signup and view all the answers

Which property is associated with the ability of metals to resist wear or deformation?

Hardness Signup and view all the answers

What is the term used to describe a metal's property that allows it to be drawn into wires?

Ductility Signup and view all the answers

Which property indicates that metals can make a ringing sound when struck?

Sonorous Signup and view all the answers

Which of the following metals is considered a noble metal due to its nonreactive nature?

Gold Signup and view all the answers

What property of metals allows them to be melted by the application of heat?

Fusibility Signup and view all the answers

Which metals are known for not corroding easily and are ideal for jewelry?

Gold and Platinum Signup and view all the answers

What is a characteristic of alkali metals?

They are very reactive. Signup and view all the answers

Which of the following metals is classified as a poor metal?

Lead Signup and view all the answers

What is the typical result when magnesium reacts with steam?

It reacts vigorously. Signup and view all the answers

What product is formed when sodium reacts with water?

Sodium Hydroxide Signup and view all the answers

Which type of metal is typically used for industrial purposes due to its strength?

Transition Metals Signup and view all the answers

What is the outcome when metals react with acids?

They produce salts and hydrogen. Signup and view all the answers

Which statement correctly describes the reactivity of metals?

Metals generally react by losing electrons. Signup and view all the answers

What is the primary cause of corrosion in metals?

Reactions with chemicals in the environment Signup and view all the answers

What is rusting specifically a term for?

The corrosion of iron Signup and view all the answers

What is the primary benefit of the layer of aluminium oxide formed on aluminium surfaces?

It provides resistance to corrosion. Signup and view all the answers

Which metal is mentioned as having high resistance to corrosion?

Gold Signup and view all the answers

Which factor is mentioned as influencing the rate of rusting?

Acid rain and salt Signup and view all the answers

Which of the following is not a main type of mining?

Underwater mining Signup and view all the answers

What does the pretreatment of ore aim to achieve?

It increases the amount of metal in ore. Signup and view all the answers

Why does aluminium not corrode in the presence of oxygen?

It forms a protective oxide layer Signup and view all the answers

In a reaction involving copper sulfate and iron, what is produced?

Iron sulfate and copper Signup and view all the answers

Which method involves using air and flotation agents to separate ore particles?

Flotation Signup and view all the answers

In the gravity concentration method, what determines how particles separate?

Weight of the particles Signup and view all the answers

What happens to metals when they corrode?

They break down and become weaker Signup and view all the answers

Which step typically comes after mining in the extraction of metals?

Pretreatment of the ore Signup and view all the answers

How does a metal's position in the reactivity series affect its corrosion resistance?

More reactive metals corrode more easily Signup and view all the answers

What is the role of the rotating drum in magnetic separation?

To hold magnetic ore particles. Signup and view all the answers

What structural arrangement do atoms in pure metals form?

Tightly-packed layers in a regular lattice Signup and view all the answers

What term describes a mineral deposit that is concentrated enough for economical recovery?

Ore Signup and view all the answers

Why are metals generally good conductors of heat and electricity?

They have delocalized electrons that transfer energy efficiently Signup and view all the answers

What property allows metals to be malleable and ductile?

Delocalized electrons allowing layers to slide over each other Signup and view all the answers

What accounts for the high melting and boiling points of metals?

Strong metallic bonding due to attraction between ions and the sea of electrons Signup and view all the answers

What structure do delocalized electrons form in metals?

A sea of electrons that moves freely Signup and view all the answers

How do metals resist shattering when force is applied?

The layers of metal ions can slide over each other Signup and view all the answers

What is the role of the 'sea of electrons' in metallic bonding?

It allows for the attraction of positively charged metal ions Signup and view all the answers

Which of the following is NOT a typical property of metals?

Brittle under pressure Signup and view all the answers

Study Notes

Metal Properties

Metals are generally solid at room temperature
They have high melting points
They are good conductors of electricity and heat
They are malleable (can be shaped)
They are ductile (can be drawn into wires)
They are strong
They are dense

Structure of Metals

Metal atoms are tightly packed in layers forming a regular lattice structure
Outer electrons of metal atoms detach and create a 'sea' of delocalized electrons
Delocalized electrons are free to move throughout the metal structure
The positive metal ions are attracted to the sea of electrons, creating metallic bonding

High Melting Points

Metals have high melting points because metallic bonding is strong
Strong attraction between positively charged metal ions and the sea of free electrons makes it difficult for the atoms to separate

Conduction of Heat and Electricity

Delocalized electrons in metals allow for efficient heat transfer throughout the structure when the metal is heated
Delocalized electrons also efficiently conduct electricity, with movement of electrons corresponding to electrical current flow

Strength and Malleability

Metallic bonds don't break when a metal is hit, allowing layers of metal ions to slide over each other
This explains why metals are malleable (easy to shape) and ductile (can be drawn into wires)

Properties of Metals

Hardness: Resistance to abrasion, penetration, and permanent distortion
Malleability: Ability to be hammered, rolled, or pressed into shapes without cracking
Ductility: Capacity to be drawn into wires
Elasticity: Ability to return to original shape after force is removed
Toughness: Resistance to tearing or shearing and deformation without breaking
Fusibility: Ability to become a liquid through heat application
Conductivity: Ability to carry heat or electricity
Luster: Shininess when cut, scratched or polished
Sonorous: Ability to create a ringing sound when hit

Metallic Bonding

True/False Statements:
- Metals have a lattice structure: True
- Metallic bonding is an attraction between metal ions: False, it's between delocalized electrons and metal ions
- Electrons have fixed places in the sea of electrons: False, electrons are delocalized
- Metallic bonding allows metals to conduct electricity: True
- Metallic bonding allows metals to be bent: True
- Metallic bonding lowers the melting point of metals: False, it increases it

Reactivity of Metals

Reactivity is the rate and ease with which an element combines with other elements to form compounds
Metals lose electrons to other atoms when reacting
Some metals react very easily, while others do not react at all with other elements.
The reactivity of metals is indicated by the reactivity series (a listing of metals in decreasing order of reactivity).

Chemical Properties of Metals

Burning: Combining with oxygen to produce metal oxides. The metal oxides are usually basic
Reactions with water: Different metals react differently with water
- Sodium reacts violently with water
- Magnesium reacts mildly with water but vigorously with steam
- Less reactive metals like copper, gold, and silver do not react with water
Reactions with acids: Produce salts and hydrogen gas. Different metals react with acids at different rates.
Replacing other metals: Some metals can displace less reactive metals in compounds; this occurs in a reaction, and is illustrated by examples.

Corrosion and Rusting

Corrosion is a gradual destruction of metal, primarily from reactions with oxygen, water, or other chemicals in the environment.
Rusting is a specific type of corrosion that occurs on iron and its alloys when exposed to water and oxygen
Rusting can be prevented by coating the metal or using other protective methods

Occurrence of Metals

Most metals are extracted from ores (mineral deposits).
An ore is a mineral deposit that contains enough of a metal to be economically extracted and refined.
Metals exist in various forms in the Earth's crust, sea water and ocean floor.

Metallurgy

Metallurgy is the scientific study of extracting and refining metals from their ores.
The process generally involves several steps including mining, ore dressing, reduction (converting from an ore to free metal), refining (purifying), and alloying (mixing with other metals for improved properties)

Mining Techniques

Open cast mining: Excavating the earth to reach the ore and overburden.
Underground mining: Excavating tunnels and shafts to uncover the ore.
Open pit mining: Creating large, open pits to extract deep ore deposits.
Dredging: Using specialized equipment in water bodies to collect the ore.
Solution mining: Using solutions to dissolve the metal to extract the ore economically.
Ore Concentration: Methods are used to concentrated the ore, such as flotation, gravity concentration to produce ore which is easier to process and use.
Magnetic Separation: Separation of magnetic ore particles from non-magnetic materials, as a means of ore concentration.

Alloys

An alloy is a metal mixture/combination where the component materials are bonded metallurgically (different than a chemical reaction)
Alloys have specific properties different from the pure metals
Steel, brass, and bronze are examples of alloys.

Summary

Metals are lustrous, malleable, ductile, hard, dense, and have high melting points.
Metals conduct heat and electricity efficiently due to delocalized electrons.
Various factors can affect reactions of metals, like reactivity series and environment
Metals exhibit different reactivity levels, influencing their behaviour.
Specific metals like gold are less reactive, explaining their resistance to corrosion.

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Description

Test your knowledge on the properties and characteristics of metals and alloys. This quiz covers various aspects including rusting, physical properties, and the behavior of different metal types. Perfect for chemistry students looking to reinforce their understanding of metals.