Category: Science
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PSLE Science Reality Lab Vol No.218 | “Tornado Rated EF3” — Was the Wind Speed Directly Measured?
A Primary 5/6 PSLE Science Reality Lab guide to tornado EF ratings: learn why an EF3 rating is inferred from surveyed damage and estimated wind ranges, not a direct wind-speed reading everywhere along the tornado path.
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PSLE Science Reality Lab Vol No.217 | “Specific Gravity = 3.0” — Is Every Piece Three Times Heavier Than Water?
A Primary 5/6 PSLE Science Reality Lab guide to specific gravity: learn why SG 3.0 is a density ratio to a reference and only implies a 3:1 mass ratio for equal volumes, not arbitrary objects.
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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.
