Transition Metals – GCSE Chemistry

Introduction

  • Metals are some of the most important materials in the world.
  • Their strength, durability, and ability to conduct heat and electricity make them very useful.
  • However, metals also have weaknesses, such as rusting, and sometimes need to be improved by mixing them with other elements.
  • In this blog, we’ll look at the properties of transition metals, the problem of corrosion, how rusting can be prevented, and why alloys are stronger and more useful in everyday life.
  • Here are some common examples that show why alloys are stronger and more useful:

Steel (iron + carbon): Stronger than pure iron, used in buildings and bridges.

Bronze (copper + tin): Harder than copper, used for statues and medals.

Brass (copper + zinc): Strong and shiny, used in musical instruments.

Transition Metals in the Periodic Table

  • Transition metals are elements found in the d-block of the Periodic Table, specifically between Group 3 and Group 12.
  • They are called transition metals because they form a “transition” between the highly reactive metals on the left and the less reactive metals and non-metals on the right.

Periodic table with transition metals highlighted in red – GCSE Chemistry diagram

What Are The Properties of Transition Metals?

  • In the middle of the periodic table, we find transition metals, which have special features that make them different from other elements:

Strength and Durability

  • Transition metals are stronger than most other metals, so they are used in construction, machines, and tools.
  • For example, iron and steel are used in bridges and tall buildings.

Illustration of a steel suspension bridge showing real-life use of transition metals in construction

Good Conductors

  • They allow heat and electricity to flow through them easily.
  • For example, electrical copper is used in wires and cooking pans.

Illustration showing copper wire and cooking pan – uses of transition metals in daily life

Malleable and Ductile

  • This means they can be hammered into thin sheets or stretched into wires without breaking.
  • Metals like gold and copper are especially good at this.

Coloured Compounds

  • Transition metals form compounds that are brightly coloured.
  • For example, copper sulfate is blue, potassium dichromate is orange, and nickel compounds are green.

Examples of coloured compounds formed by transition metals – blue, orange, and green crystals

Catalysts

  • Some transition metals help reactions happen faster without getting used up.
  • For example, iron is used in making ammonia, and platinum helps reduce car pollution.

What is Corrosion of Metals?

  • When metals are slowly damaged by chemical reactions with substances in their surroundings, such as air, water, or acids, it is called corrosion.
  • The most common example of corrosion is rusting of iron.
  • When iron reacts with Oxygen and water, it forms reddish-brown flakes called rust.
  • Rust is soft and crumbly, so instead of protecting iron, it makes the metal weaker.

Balanced chemical equation for rusting of iron showing reaction with oxygen and water

  • This changes into Fe₂O₃·xH₂O (hydrated iron(III) oxide), which we call rust.

Here are some different types of corrosion on metals:

Iron:

  • Rust – the reddish-brown corrosion that weakens bridges, car etc.

Rusted bolts and nuts showing corrosion of iron – example of transition metal reaction with oxygen and water

Copper:

  • Patina – a green layer that develops on old roofs and statues.

Flaking green paint revealing corroded metal underneath – example of rust prevention breakdown

Silver:

  • Tarnish – a black coating formed by silver sulfide.

Old silver spoons showing tarnish due to silver sulfide corrosion – example of transition metal reaction

Aluminium:

  • Aluminium oxide – a thin, protective layer that stops further corrosion.

Close-up of layered, flaking rust on metal surface – severe corrosion of transition metal

What Are The Methods of Preventing Rusting?

  • There are different methods we can use to prevent rusting. Here they are:

Painting and Plastic Coating

  • A layer of paint or plastic is used on car bodies, fences, etc., which keeps out air and water.

Painting a car and a wooden fence to prevent rust and corrosion – GCSE Chemistry rust prevention example

Oiling or Greasing

  • It is commonly used for machine parts and bicycle chains.
  • The oil prevents water and oxygen from reaching the metal.

Close-up of greased gears in machinery – oiling method to prevent rusting of metal parts

Galvanising

  • When iron is coated with a layer of zinc, it is called galvanising.
  • The zinc protects the iron by forming a barrier, and even if it is scratched, zinc reacts more easily than iron, so it prevents rusting.

Side-by-side image showing rusted corrugated iron sheet and corrosion-resistant stainless steel plate

Electroplating

  • Using electricity, a thin layer of another metal such as chromium or silver is coated onto iron or steel.
  • This protects it from rust and also makes it look better.

Industrial processes of electroplating and alloying metals – used to prevent corrosion and improve properties

Alloying

  • When iron is mixed with other metals, such as chromium and nickel, it makes stainless steel.
  • This process is called alloying, and the steel does not rust easily, so it is used in cutlery, sinks, and medical tools.

Image showing stainless steel pipes and a silver alloy car wheel – uses of transition metal alloys

What Makes Alloys Stronger?

  • Pure metals are not always suitable for everyday use, so alloys are made to improve their strength and usefulness.
  • Here are the main reasons why alloys are stronger than pure metals:

Diagram comparing atomic arrangement in pure metals and alloys – GCSE Chemistry particle model

Pure Metals are too Soft

  • On their own, many pure metals bend or wear out quickly, so they are not always useful for construction or tools.

Alloys are Mixtures

  • When metals are mixed with other metals (or non-metals), the new material is usually stronger and more durable.

Layers in Pure Metals Slide Easily

  • Because all atoms are the same size and neatly arranged, the layers can slip over each other, making the metal soft.

Different Atom Sizes in Alloys

  • When other elements are added, they break the regular pattern of atoms, so the layers can’t slide easily.
  • This makes the alloy harder and stronger.

Examples of alloys:

  • Pure iron is soft and bends easily.
  • Adding small amounts of carbon makes steel, which is much stronger.
  • Adding chromium and nickel makes stainless steel, which is both strong and resistant to rust.

What Are The Types of Alloy Steels?

  • Steel is an alloy of iron and carbon.
  • By adding other elements, we can make different types of steel with special properties.
  • Here are some examples:

Stainless Steel

  • Made with chromium and nickel.
  • It is commonly used in cutlery, kitchen sinks, medical instruments, etc., because it doesn’t rust easily.

Stainless steel utensils and cookware – practical use of transition metal alloys in households

High-Carbon Steel

  • It contains more carbon, which makes it very hard and strong.
  • It is used for knives, drills, and other cutting tools.

Set of sharp steel knives and a drill with steel bit – uses of transition metals in tools

Low-Carbon Steel

  • It contains less carbon, which makes it softer and easier to shape.
  • It is used in car bodies and household appliances.

Cartoon illustration of a car body and kitchen cutlery – showing transition metals in everyday items

Tool Steel

  • It contains elements like tungsten and vanadium, which make it tough and heat-resistant.
  • It is used in machine parts and tools.

Cartoon illustration of rusty machine parts and a toolbox with tools – showing uses of transition metals like iron and titanium

What Are The Uses of Metals and Alloys?

  • Metals and alloys are everywhere in daily life:

Construction

  • Steel is used for bridges, buildings, and railways because it is strong and durable.

Cartoon illustration of a construction site with cranes, buildings, and workers – highlighting the use of transition metals like iron and titanium in construction materials

Transport

  • Aluminium is used for aircraft because it is lightweight, while steel is used for ships and cars for strength.

Cartoon icons of an airplane, cargo ship, and delivery truck – showing the use of transition metals like titanium, iron, and copper in transport vehicles

Electrical uses

  • Copper is used in wires and electrical circuits because it conducts electricity very well.

Cartoon image of twisted metal wire and an electrician working on a power box, representing transition metals like copper used in electrical wiring

Household items

  • Stainless steel is used in cutlery, pans, sinks, and appliances.

Cartoon image of a frying pan and a kitchen sink showing transition metals like iron and stainless steel used in cookware and plumbing

Jewellery and Decoration

  • Gold, silver, and platinum are used in jewellery.
  • Cheaper items are often electroplated to look more expensive.

Cartoon image of a gold ring and a silver ring representing transition metals used in jewellery like gold and silver

Coins

  • Made of different alloys to be strong and long-lasting.

Frequently Asked Questions

Solution:

Transition metals are elements found in the centre of the periodic table that form coloured compounds and have variable oxidation states.

Solution:

They are found in the middle block (Groups 3–12) of the periodic table.

Solution:

They are hard, strong, shiny, good conductors of heat and electricity, and have high melting points.

Solution:

Because they are strong and durable, they are used in buildings, cars, and machinery.

Solution:

Corrosion is the gradual destruction of metals by reacting with air or water, such as the rusting of iron.

Solution:

Rusting is a type of corrosion where iron reacts with oxygen and water to form hydrated iron(III) oxide (rust).

Solution:

Rusting can be prevented by painting, oiling, galvanising, or coating the metal to stop oxygen and water from reaching it.

Solution:

In alloys, different-sized atoms make it harder for metal layers to slide over each other, increasing strength and hardness.

Solution:

Alloy steels are steels mixed with other elements like chromium or nickel to improve properties such as strength and resistance to rust.

Solution:

Metals and alloys are used in construction, transport, electrical wiring, coins, tools, and jewellery due to their strength and conductivity.