Where the transition metals sit, how their properties differ from Group 1, why they make good catalysts and how their compounds are coloured.
Objectives
Locate the transition metals in the periodic table.
Compare the physical and chemical properties of transition metals with Group 1 metals.
State typical properties of transition metals: ions with different charges, coloured compounds and use as catalysts.
Link the properties of copper and iron to their uses.
Transition metals explained
Start here
Iron in a bridge, copper in a wire and gold in a ring are all transition metals. They are the strong, shiny metals you meet in everyday life.
This matters because they are so useful. They hold up buildings, carry electricity and speed up reactions in factories. Knowing why helps you choose the right metal for a job.
By the end you will be able to find them in the periodic table. You will compare them with Group 1 metals. You will describe their typical properties. You will link those properties to their uses.
The central block
The periodic table has a block of metals in the middle. These are the transition metals. They sit between Group 2 and Group 3.
Iron, copper, nickel, chromium, manganese, silver and gold are all examples.
Transition metals behave like typical metals. They are shiny and they conduct heat and electricity. They are malleable, which means they can be hammered into shape. They are also ductile, which means they can be pulled into wires.
Compared with Group 1
Group 1 metals are soft. You can cut them with a knife. They have low melting points and low densities. Density is how much mass fits into a given volume.
Transition metals are harder, denser and stronger. The chart shows potassium and sodium melting below 100 °C. Copper and iron melt above 1000 °C.
Group 1 metals are very reactive. Transition metals are much less reactive. They react slowly or not at all with water and oxygen at room temperature. They do not react violently like sodium or potassium.
Bars comparing melting points in degrees Celsius: potassium 63, sodium 98, copper 1085 and iron 1538.
Physical properties and uses
Most transition metals have high melting points. Iron melts at 1538 °C and copper at 1085 °C. They are also strong and hard. Mercury is the exception, because it is a liquid at room temperature.
These properties make them useful. Iron is used for tools and building because it is strong. Copper conducts electricity well and can be bent, so it is used for electrical wiring and water pipes.
Think of a frying pan. It must not melt on a hot hob, so it needs a high melting point.
Transition metals as catalysts
A catalyst speeds up a reaction without being used up. Many transition metals and their compounds are good catalysts.
Iron is the catalyst in the Haber process, which makes ammonia. Nickel is the catalyst when vegetable oils are hardened with hydrogen to make margarine.
Factories use catalysts because they let reactions run faster at lower temperatures. This saves energy and money. A catalyst is like a helper who makes a job quicker but does not get used up like the ingredients.
Ions and coloured compounds
Transition metals can form ions with different charges. An ion is an atom with an electric charge. Iron forms Fe²⁺ and Fe³⁺. Copper forms Cu⁺ and Cu²⁺.
The name shows the charge with a Roman numeral. Iron(II) chloride contains Fe²⁺. Iron(III) chloride contains Fe³⁺. The number in brackets is the charge on the ion, so (II) means 2+ and (III) means 3+.
Their compounds are usually coloured. Copper(II) compounds are blue. Iron(II) compounds are green. Iron(III) compounds are orange-brown. Group 1 compounds are white.
Choosing a metal for the job
Iron is strong and cheap, so it is used for bridges and cars, usually as steel. Copper is used for wires and pipes. Chromium is used to plate steel to stop it rusting and to make it shiny.
To choose a metal, match the property to the job. A bridge needs strength. A wire needs to conduct electricity and bend. A pipe needs to resist corrosion.
It is like picking a tool from the kitchen drawer. You choose the one whose shape and strength suit the job.
Recap
Transition metals are in the central block, between Group 2 and Group 3.
Compared with Group 1, they are harder, denser and stronger, with higher melting points and lower reactivity.
They form ions with different charges, and their compounds are usually coloured. Many are good catalysts.
Match the property to the use. Iron is strong and cheap. Copper conducts and bends.
Key points
Transition metals are in the central block between Group 2 and Group 3.
Compared with Group 1 they are harder, denser, stronger, less reactive and have higher melting points.
They form ions with different charges and coloured compounds.
Many are catalysts, such as iron in the Haber process and nickel for hardening oils.
Worked examples
Example 1
Give one physical property that transition metals have and Group 1 metals do not.
Group 1 metals are soft with low melting points.
Transition metals are hard and strong with high melting points.
One property is a high melting point.
Answer: a high melting point
Common slips
Slip: Both are shiny and conduct electricity. These are shared properties, not differences.
Slip: Transition metals are softer. Transition metals are harder than Group 1 metals.
Slip: A low density. Transition metals have higher densities than Group 1.
Example 2
A block of iron has a mass of 237 g and a volume of 30 cm³. Calculate its density in g/cm³.
density = mass ÷ volume.
Substitute: 237 ÷ 30.
Density = 7.9 g/cm³.
Answer: 7.9 g/cm³
Common slips
Slip: density = volume ÷ mass. Density is mass divided by volume.
Slip: 237 × 30 = 7110. You divide to find the mass per cm³.
Slip: Density = 0.13 g/cm³. That is volume ÷ mass. The right way round gives 7.9.
Example 3
Explain why a nickel catalyst is used in industry, and give one other property of transition metal compounds.
A catalyst speeds up a reaction without being used up.
This lets the reaction run faster or at a lower temperature, which saves energy and money.
Another property is that the compounds are coloured.
Answer: It speeds up the reaction without being used up, saving energy and money. Transition metal compounds are coloured.
Common slips
Slip: A catalyst is used up so it must be replaced. A catalyst is not used up. It can be used again.
Slip: A catalyst makes the reaction give more product. It speeds up the reaction. It does not change the amount of product.
Slip: The compounds are white. Transition metal compounds are usually coloured. White is typical of Group 1.
Questions and answers
Transition metals practice questions for GCSE Combined Science Chemistry. Try each one, then open the answer. Easy questions come first.
Question 1 Easy
Name a transition metal that is used in electrical wiring.
Show answer
Answer: copper
It must conduct electricity well.
Copper is used.
Question 2 Easy
Do transition metals have higher or lower melting points than Group 1 metals?
Show answer
Answer: higher
Group 1 metals melt easily.
Transition metals need much more heat.
Question 3 Easy
What colour are copper(II) compounds?
Show answer
Answer: blue
Copper sulfate crystals are a familiar example.
They are blue.
Question 4 Easy
Name the transition metal used as the catalyst in the Haber process.
Show answer
Answer: iron
Ammonia is made using this catalyst.
It is iron.
Question 5 Easy
Are the transition metals in the middle of the periodic table or on the far right?
Show answer
Answer: the middle
They form a block between Group 2 and Group 3.
So they are in the middle.
Question 6 Easy
Name the transition metal that is a liquid at room temperature.
Show answer
Answer: mercury
Most transition metals are solid.
The exception is mercury.
Question 7 Medium
A piece of copper has a mass of 89 g and a volume of 10 cm³. Calculate its density in g/cm³.
Show answer
Answer: 8.9 g/cm³
density = mass ÷ volume.
89 ÷ 10 = 8.9.
Question 8 Medium
Give the charge on the iron ions in iron(III) oxide.
Show answer
Answer: 3+
The Roman numeral gives the charge.
III means 3+.
Exam-style questions
Longer questions in the style of a written paper, with the marking points. These are Yumio practice questions.
Exam-style question 14 marks
Sodium is a Group 1 metal and iron is a transition metal.
(a) Give two differences between the physical properties of sodium and iron. [2 marks]
(b) Give two differences in the way they react with water. [2 marks]
Show answer and marking points
Answer: (a) Iron is harder and has a much higher melting point. (b) Sodium reacts vigorously, making hydrogen, but iron reacts very slowly or not at all.
(a) iron is harder or stronger (1)
(a) iron has a higher melting point or higher density (1)
(b) sodium reacts vigorously or fizzes (1)
(b) iron reacts very slowly or not at all (1)
Exam-style question 24 marks
(a) State two typical properties of transition metal compounds. [2 marks]
(b) Iron is used as a catalyst in the Haber process. Explain why a catalyst is used. [2 marks]
Show answer and marking points
Answer: (a) They are coloured and the metals form ions with different charges. (b) A catalyst speeds up the reaction, so the process can run at a lower temperature, saving energy.
(a) compounds are coloured (1)
(a) ions with different charges, or use as catalysts (1)
(b) speeds up the reaction (1)
(b) lower temperature or less energy, so lower cost (1)
Common mistakes
Saying transition metals are more reactive than Group 1
They are much less reactive.
Saying a catalyst is used up in the reaction
A catalyst is not used up. It speeds up the reaction and can be reused.
Saying all transition metal compounds are white
They are usually coloured, for example blue copper(II) sulfate.
Forgetting that transition metals can form more than one ion
Iron forms Fe²⁺ and Fe³⁺. The Roman numeral shows the charge.
Questions students ask
Is Transition metals on the Foundation or Higher tier?
Transition metals is on both Foundation and Higher papers for GCSE Combined Science Chemistry, aimed at around grade 5.
What is a common mistake on Transition metals?
Saying transition metals are more reactive than Group 1. They are much less reactive.
Where are the answers to the Transition metals questions?
Open Show answer under each question on this page. The questions are Yumio practice questions, not past exam questions.