1.6 The Periodic Table
Development and organisation of the Periodic Table, metals and non-metals, Groups 1, 7 and 0, transition elements and trend explanations.
How to study for CCEA GCSE Chemistry
Connect particle models to observations, balance every quantitative relationship, and prepare each prescribed practical from safe method through analysis and evaluation.
Core concepts
Concept 1
The modern Periodic Table orders elements by atomic number so repeating outer-electron structures produce repeating chemical properties.
Exam cue: Use electron arrangement to predict group, period and likely ion charge.
Concept 2
Group 1 reactivity increases down the group, while Group 7 reactivity decreases; explanations use shielding, distance and nuclear attraction.
Exam cue: For a trend, state what changes down the group and how that changes electron loss or gain.
Concept 3
Group 0 elements are unreactive because they have stable outer shells, while transition elements show characteristic metallic and catalytic behaviour.
Exam cue: Use displacement evidence to order halogen or metal reactivity.
Risk pitfalls and guardrails
Explaining all trends only by saying atoms get bigger.
Guardrail: Do not import an England board, Single Award or Double Award structure, and do not replace a particle-level explanation with a vague observation.
Reversing the Group 1 and Group 7 reactivity trends.
Guardrail: Do not import an England board, Single Award or Double Award structure, and do not replace a particle-level explanation with a vague observation.
Treating Mendeleev's table as already ordered by atomic number.
Guardrail: Do not import an England board, Single Award or Double Award structure, and do not replace a particle-level explanation with a vague observation.
Memory anchors
Periodic law
Element properties repeat when elements are arranged by atomic number.
Group 1
Reactive metals forming positive one ions; reactivity increases down the group.
Group 7
Reactive diatomic non-metals forming negative one ions; reactivity decreases down the group.
Group 0
Elements with complete outer shells and very low chemical reactivity.
Displacement
A more reactive element replaces a less reactive element from a compound.
Transition element
A central-block metal often showing variable ions, coloured compounds or catalytic action.
Checkpoint rule
Do the check-up only after you can summarize each concept in one sentence and identify one dangerous pitfall from memory.
Knowledge Check (after reading)
Short check-up to confirm understanding of this module.
Check-up Questions
Why did Mendeleev leave gaps in his table?
How is the modern Periodic Table ordered?
Answer all questions to submit.
Next step personalized recommendations
Continue learning
Move forward only after this module is stable.
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