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Science Through Examples teaches physics, chemistry, and biology through simple explanations, worked examples, and connections that help students understand concepts instead of merely memorizing them.

Bancada de química com modelos moleculares, vidrarias e lousa exibindo a equação 2 H₂ + O₂ → 2 H₂O e uma tabela de contagem de átomos.

Chemistry22/09/2026

Balancing chemical equations: how to adjust coefficients without changing formulas

Learn to balance chemical equations by preserving formulas, counting atoms, and changing only coefficients, with worked examples that increase in difficulty.

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Bancada didática com circuitos de baixa tensão em série e em paralelo, lâmpadas acesas, multímetro, esquemas elétricos e caderno com fórmulas.

Physics22/09/2026

Series and parallel circuits: how to calculate current, voltage, and resistance step by step

Learn how to identify each connection, calculate equivalent resistance, current, and voltage, and check the result with two low voltage examples.

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Bancada de laboratório com pipeta, béqueres, balão volumétrico e proveta com soluções azuis, acompanhados da equação C1V1=C2V2 e indicações de unidades.

Chemistry14/09/2026

Dilution without memorizing: how to use C1V1=C2V2, get the units right, and know when it does not apply

Understand where C1V1=C2V2 comes from, how to check units and final volume, solve three common problem types, and recognize situations where the dilution equation does not apply.

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Dois meninos gêmeos lado a lado, com uma hélice de DNA ao fundo e impressões digitais ampliadas por uma lupa.

Biology13/09/2026

Do identical twins have the same fingerprints? Genes influence them, but development creates differences

Monozygotic twins share nearly all of their DNA and tend to have more similar fingerprints, but not identical ones. Learn how genes, fetal ridge formation and microscopic developme...

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Bloco de gelo flutuando na água, com parte submersa e dois detalhes moleculares mostrando a rede hexagonal aberta do gelo e moléculas mais compactas na água líquida.

Chemistry13/09/2026

Why Does Ice Float? Hydrogen Bonds, Water Expansion, and Density

Learn why water expands when it freezes, how hydrogen bonds create an open lattice, and why that structure makes ice less dense than liquid water.

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Pés sobre uma balança digital com detalhe do sensor de força e comparação visual da gravidade na Terra e na Lua.

Physics13/09/2026

Does a scale measure mass or weight? Why it senses force but displays kilograms

A common scale’s sensor responds to a support force; its electronics use calibration to display a mass value in kilograms.

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Duas mãos tocam lado a lado uma placa de metal e um bloco de madeira sobre uma mesa, com um termômetro desfocado ao fundo.

Physics12/09/2026

Why metal feels colder than wood at the same temperature: thermal effusivity explained

Metal and wood can be at the same temperature yet feel very different. Learn how heat flow, conductivity, and thermal effusivity shape touch — and try a simple test.

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Tigela de vidro com cubos de gelo recebendo sal grosso, com pote de sal, colher de madeira e termômetro sobre uma mesa.

Chemistry12/09/2026

Why salt melts ice and the mixture drops below 0 °C

Learn how freezing-point depression lets an ice-salt mixture fall below 0 °C, with a simple experiment, an approximate calculation, and the limits of the ideal model.

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Panela de pressão de aço inox sobre chama azul, liberando vapor pela válvula em uma cozinha com vegetais ao fundo.

Physics12/09/2026

Why Does a Pressure Cooker Cook Faster? Pressure, Boiling Point and a Numerical Example

Learn how pressure raises water's boiling point, why cooking near 121 °C speeds food preparation, and what a simple energy calculation shows.

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Estudante diante de um notebook com painéis digitais de gráficos, fluxograma, programação em blocos e depuração de uma solução.

Scientific Foundations10/09/2026

PISA 2025: what computational problem solving is and which tasks measure the skill

Learn how PISA 2025 assesses computational problem solving through experiments, data analysis, modelling, building and debugging in digital tasks.

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Estudante analisando três gráficos simples de ciências em um tablet, cercada por materiais escolares, microscópio e elementos visuais sobre PISA 2025.

Scientific Foundations10/09/2026

PISA 2025: what science Level 2 requires — 3 examples for testing conclusions with data

Understand PISA 2025 science Level 2 and practise, with three original situations, how to decide whether a conclusion is supported by data.

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Terra vista do espaço com o Brasil em destaque no limite entre dia e noite e um detalhe conceitual mostrando a refração da luz solar no horizonte.

Physics10/09/2026

September 2026 equinox: why day and night are not exactly 12 hours in Brazil

The equinox occurs at 00:05 UTC on Sep. 23, but in Brazil it falls on the evening of Sep. 22, and sunrise-to-sunset daylight exceeds 12 hours because of refraction and the definiti...

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