PDF pp. 4–6: chemistry, optics and electrical topics. Unit listing and teacher assessment note conflict for current effects; these activities make no examination-inclusion claim.
Inspected 2026-10-23Carbon’s four-bond budget
Why does an extra carbon–carbon bond reduce the hydrogen count?
Set up your investigation
Construct a straight open carbon chain with one selected single, double or triple bond and satisfy each carbon’s valence.
Write at least 8 characters. Each trial keeps its own inputs; later control changes do not rewrite earlier observations.
Observe the model
Your experiment starts with a prediction.
Set the controls above and run a trial. A diagram, exact quantities and an explanation will appear here.
EVIDENCE, SIDE BY SIDE
Your laboratory notebook
Keep up to 8 trials for this investigation. Compare two recorded observations with exactly one changed control. Writing is saved as participation evidence.
No trials yet. Start with the setup above.
A controlled comparison needs two observations with exactly one changed input.
Test your reasoning
Use at least 40 characters, a result from each trial and one model limitation. Your writing is not automatically graded.
Build your investigation evidence
- ○ Two observed trials with one changed control
- ○ Mechanism / reasoning check
- ○ Written explanation of at least 40 characters
These practice markers recalculate when evidence changes. They are not an official grade or a claim of mastery.
Curriculum and provenance
This is an original working investigation. Its selected source context does not establish full chapter coverage, official endorsement or prescribed-practical status. Detailed objective mapping remains provisional. Qualified subject-educator review is pending.