Category: Science
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PSLE Science Reality Lab Vol No.216 | “99.9% Pure” — Pure by What Measure, and What Is in the Other 0.1%?
A Primary 5/6 PSLE Science Reality Lab guide to purity claims: learn why “99.9% pure” needs a defined substance, fraction basis and method, and why it does not identify the remaining 0.1% or prove safety.
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PSLE Science Reality Lab Vol No.215 | “Mohs Hardness = 8” — Is It Twice as Hard as Mohs 4?
A Primary 5/6 PSLE Science Reality Lab guide to Mohs hardness: learn why Mohs 8 is not twice Mohs 4, and why scratch hardness must not be confused with toughness or overall durability.
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PSLE Science Reality Lab Vol No.214 | “CRI = 90” — Does That Mean Colours Are 90% Accurate?
A Primary 5/6 PSLE Science Reality Lab guide to lamp labels: learn why CRI 90 is a colour-rendering score under a defined comparison method, not 90% colour accuracy, brightness or efficiency.
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PSLE Science Reality Lab Vol No.213 | “Capacity Factor = 30%” — Is the Generator Only 30% Efficient?
A Primary 5/6 PSLE Science Reality Lab guide to electricity reports: learn why a 30% capacity factor compares actual generation with full-rated generation over time, not conversion efficiency.
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PSLE Science Reality Lab Vol No.212 | “Volcano Alert Level = WATCH” — Does That Mean an Eruption Is Certain?
A Primary 5/6 PSLE Science Reality Lab guide to volcano alerts: learn why WATCH is a status category based on observed unrest and hazard assessment, not a guarantee, probability percentage or eruption-size score.
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PSLE Science Reality Lab Vol No.211 | “Secchi Depth = 2 m” — Is the Lake Only 2 m Deep?
A Primary 5/6 PSLE Science Reality Lab guide to Secchi depth: learn why a 2 m reading describes water clarity under stated observation conditions, not the physical depth of the lake.
