Who this is for: Cambridge IGCSE Coordinated Science (0654) students who want the periodic table — groups, periods and property trends — to become a reliable source of marks instead of a position-memorising exercise.
What query it owns: how to understand and revise the periodic table in Cambridge IGCSE Coordinated Science.
Why this is safe: this page owns the periodic-table revision-guide angle, while Tutopiya’s The Periodic Table subtopic page owns the learning resource and the free Periodic Table quiz owns the practice.

The periodic table arranges elements by atomic number and reveals patterns in properties. Cambridge IGCSE Coordinated Science (0654) expects you to use group numbers to predict valency, describe trends in reactivity down Groups I and VII, and explain differences between metals and non-metals. This guide links layout to the predictions examiners reward.

Key takeaways

• Elements are arranged by increasing atomic number (proton number).
• Groups (columns) contain elements with similar chemical properties; periods are rows.
• Group I metals increase in reactivity down the group; react with water → alkali + hydrogen.
• Group VII halogens decrease in reactivity down the group; form diatomic molecules (X₂).
• Transition elements are metals between Groups II and III with variable valency and coloured compounds.

What is the periodic table in Cambridge IGCSE Coordinated Science?

The modern periodic table orders elements by proton number. Elements in the same group have the same number of outer-shell electrons, giving similar chemistry. Moving across a period, elements change from metal to non-metal. Trends in reactivity, melting point and bonding can be predicted from position.

You can read the full explanation, diagrams and notes on Tutopiya’s The Periodic Table subtopic page before you attempt questions.

Layout — groups and periods

Feature	Definition	Significance
Group number	Vertical column (I–VII, 0)	Same outer electrons → similar properties
Period number	Horizontal row	Same number of electron shells
Atomic number	Proton number	Determines position and identity
Relative atomic mass	Average mass of isotopes	Shown in most tables

Key group trends

Group	Name	Trend down the group	Key reaction
I	Alkali metals	Reactivity increases	Metal + water → MOH + H₂
VII	Halogens	Reactivity decreases	Halogen + metal → metal halide
0	Noble gases	Unreactive (full outer shell)	Rarely form compounds

Metals vs non-metals — general properties

Property	Metals	Non-metals
Electrical conductivity	Good (solid)	Poor (except graphite)
Melting point	Generally high	Generally low
Oxides	Basic (often)	Acidic (often)
Reaction with acids	Reactive metals react	Do not react
Position	Left and centre	Right side

The periodic table in past-paper wording

Command word	What the question wants	Typical stem
Predict	Property from position	”Predict the reactivity of rubidium with water.”
Explain	Trend using electron shells	”Explain why reactivity increases down Group I.”
State	Group, period or property	”State the group number of fluorine.”
Compare	Two elements in same group	”Compare chlorine and iodine reactivity.”

Worked exam-style stems

1. “Explain why alkali metals become more reactive down Group I.” Each element has one more electron shell; the outer electron is further from the nucleus and more easily lost. Reward: more shells + outer electron further + easier to lose.
2. “Predict the products when sodium reacts with water.” Sodium hydroxide and hydrogen gas. Reward: NaOH + H₂.
3. “State two properties of transition elements.” Any two: variable valency, coloured compounds, catalysts, high density, high melting point. Reward: any two valid properties.

Test yourself with the Periodic Table quiz once you can predict properties from group and period.

How the periodic table connects to the syllabus

Periodic trends underpin metal reactivity, oxide types, electrolysis predictions and salt preparation. Group VII links to halogen displacement reactions. The Cambridge IGCSE Coordinated Science resource hub links every Periodic Table subtopic.

Common mistakes students make

• Confusing group number with number of electron shells (period = shells).
• Stating halogens become more reactive down the group (reactivity decreases).
• Forgetting Group 0 elements are monatomic and unreactive.
• Placing hydrogen with alkali metals without noting its unique position.
• Mixing up atomic number and mass number.

When you need more support

If periodic trend questions keep costing marks, work through the Periodic Table quiz, then get focused help from a Cambridge IGCSE Coordinated Science tutor.

Frequently asked questions

Is the periodic table hard in Coordinated Science? Group trends follow clear rules — link position to outer electrons and reactivity.

Why do elements in the same group have similar properties? They have the same number of electrons in their outer shell.

How does reactivity change down Group VII? Reactivity decreases — larger atoms attract electrons less strongly.

How do I revise the periodic table effectively? Learn Group I, VII and 0 trends, metals vs non-metals, transition element properties, then take the quiz.

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