Science 6: Matter, Energy & Earth Systems — Sample Exam worked answers
Student exam paperOriginal Grade 6 home-study paper with complete supplied scenarios, calculations, and scientific explanation. It samples the course and does not replace review of the investigation notebook.
8 questions · 24 points · suggested 45 minutes
Student instructions
- Work independently after agreeing timing and access support with a parent; record any support used.
- All scenario numbers and records are illustrative. Use the stated assumptions and do not invent missing data.
- Use the reference relationships below and a basic calculator when helpful. Show a calculation, retain units, and explain what it means.
- For concept questions, connect a claim with the relevant mechanism or evidence and a specific limit. A supported alternative can satisfy the criteria.
- Keep the answer key and lesson models closed during an independent attempt. Discuss corrections after human marking.
- Use saved investigation plans, observations, revised models, projects, and an oral conference as additional assessment evidence.
Measurement and model relationships
| Relationship | How to use it |
|---|---|
| Length | 10 mm = 1 cm; 100 cm = 1 m |
| Mass and volume | 1,000 g = 1 kg; 1,000 mL = 1 L |
| Mean | Sum comparable values and divide by their count |
| Density | Mass ÷ volume; preserve units such as g/mL or g/cm³ |
| Percentage | Part ÷ stated whole × 100; identify the denominator |
| Change/rate | Ending minus starting value; divide a stated change by its time interval |
| Tidal range | High water minus low water with the same reference |
| Space scale | Actual stated distance ÷ actual km per model cm |
| Energy account | Include relevant stores and transfers; °C is not a joule value |
Coverage and marks
| Chapter | Questions | Points |
|---|---|---|
| Chapter 1 · Inquiry, Measurement & Models | 1 | 3 |
| Chapter 2 · Matter, Mixtures & Water Properties | 2 | 3 |
| Chapter 3 · Energy, Heat & Thermal Design | 3 | 3 |
| Chapter 4 · Electricity, Magnetism & Light | 4 | 3 |
| Chapter 5 · Earth Systems, Plates & Earth Materials | 5 | 3 |
| Chapter 6 · Water, Air, Weather & Climate | 6 | 3 |
| Chapter 7 · Ecosystems, Watersheds & Conservation | 7 | 3 |
| Chapter 8 · Earth, Moon, Sun & Space Models | 8 | 3 |
Parent / teacher marking guide
- Each written task has three separate one-point criteria. Award for meaning and reasoning, not keyword matching.
- A different accurate supported answer may receive full credit. Do not require personal or political agreement.
- Keep written marks pending until reviewed by a person. Record the criteria met and one improvement.
- Compare exam evidence with the notebook and project process rather than certify mastery from one total.
Question 1 · 3 points
A ruler’s start is 2.2 cm and end 9.0 cm. Find length in cm/mm and explain why the physical ruler edge need not be zero.
Worked answer
The length is 6.8 cm or 68 mm. Use the marked start/end or correct the offset rather than assume the ruler’s physical edge is its zero mark.
Compare each criterion with the learner’s actual reasoning. Accurate supported alternatives may receive full credit. Written answers require human marking.
Marking criteria
- 1 point: Calculate 6.8 cm.
- 1 point: Convert 68 mm.
- 1 point: Explain zero/offset method.
Question 2 · 3 points
A mixture contains 40 g water, 3 g dissolved salt, and 7 g sand. The model removes all sand and later evaporates all water. Account for final destinations and reject a destroyed-water claim.
Worked answer
Final destinations are 7 g sand, 3 g salt, and 40 g water transferred into air, totaling the initial 50 g. Evaporation changes location/state rather than destroy water; clarity also is not safety certification.
Compare each criterion with the learner’s actual reasoning. Accurate supported alternatives may receive full credit. Written answers require human marking.
Marking criteria
- 1 point: Account for sand and salt.
- 1 point: Account for transferred water and 50 g total.
- 1 point: Correct destruction or unsafe purity inference.
Question 3 · 3 points
A model receives 90 J and gives 18 J light plus 72 J thermal output. Calculate light fraction and explain why a lighting loss is not destroyed energy.
Worked answer
18 ÷ 90 = 20%, and 18 + 72 = 90 J. Thermal output remains energy even when it is less useful for this lighting purpose.
Compare each criterion with the learner’s actual reasoning. Accurate supported alternatives may receive full credit. Written answers require human marking.
Marking criteria
- 1 point: Calculate 20%.
- 1 point: Account for 90 J.
- 1 point: Explain purpose-dependent usefulness and conservation.
Question 4 · 3 points
A ray has 45° incidence from the normal at an ideal plane mirror. Give reflection angles from normal/surface and explain how rough paper remains visible.
Worked answer
The reflection is 45° from the normal and 45° from the surface. Rough paper scatters arriving light toward observers rather than need emit its own light.
Compare each criterion with the learner’s actual reasoning. Accurate supported alternatives may receive full credit. Written answers require human marking.
Marking criteria
- 1 point: Give 45° normal reflection.
- 1 point: Give 45° surface angle with correct reference.
- 1 point: Explain diffuse reflected light and vision.
Question 5 · 3 points
Marker separation grows from 120 to 132 cm over six years. Calculate mean relative rate and explain why it is not a clock for the next earthquake.
Worked answer
The relative rate is 12 ÷ 6 = 2 cm/year. It describes those markers and interval, not every individual plate speed or the exact buildup/release of stress for a future event.
Compare each criterion with the learner’s actual reasoning. Accurate supported alternatives may receive full credit. Written answers require human marking.
Marking criteria
- 1 point: Calculate 12 cm change.
- 1 point: Calculate 2 cm/year.
- 1 point: State a specific event-prediction or individual-motion limit.
Question 6 · 3 points
Matched long-period seasonal means rise from 10.5 to 11.2 °C. A chilly afternoon is recorded. Explain the difference, scale, and why neither record alone establishes the cause.
Worked answer
The means differ by 0.7 °C. Long-term climate summaries coexist with variable short-term weather. Attribution needs mechanisms and broader evidence, not one selected day or a graph’s shape alone.
Compare each criterion with the learner’s actual reasoning. Accurate supported alternatives may receive full credit. Written answers require human marking.
Marking criteria
- 1 point: Calculate 0.7 °C.
- 1 point: Explain climate versus weather variability.
- 1 point: Identify attribution/evidence limit.
Question 7 · 3 points
Oxygen samples are 5, 6, 7 mg/L. Find the mean and explain why a missing next sample is not zero and a clear appearance is not drinking certification.
Worked answer
Mean is 6 mg/L. The missing sample is unmeasured, not observed zero. Limited indicators and visual clarity do not establish every microbial or chemical safety requirement.
Compare each criterion with the learner’s actual reasoning. Accurate supported alternatives may receive full credit. Written answers require human marking.
Marking criteria
- 1 point: Calculate 6 mg/L.
- 1 point: Distinguish missing from zero.
- 1 point: Explain indicator/safety limit.
Question 8 · 3 points
At 1 cm per 5,000,000 km, a supplied 75,000,000 km separation is drawn as 15 cm. Check it and explain why a much enlarged planet symbol needs a separate label.
Worked answer
75,000,000 ÷ 5,000,000 = 15 cm, matching the distance scale. A large planet symbol may use a different size scale for visibility; label that exaggeration before using the drawing for diameter comparisons.
Compare each criterion with the learner’s actual reasoning. Accurate supported alternatives may receive full credit. Written answers require human marking.
Marking criteria
- 1 point: Check 15 cm calculation.
- 1 point: Distinguish size scale from distance scale.
- 1 point: Explain honest labels and numerical purpose limits.