Recursos cambios químicos

La diferenciación entre cambios químicos y físicos es algo básico que se introduce en varios niveles.
Primero se introducen como cambios químicos y luego se habla de reacciones químicas.
Aparece en Currículo Física y Química 2º ESO
La idea de exotérmico y endotérmico se introduce en ESO y luego se trata con cálculos en termoquímica

Hay recursos asociados en

Vídeo con conservación masa gráfica
Watch the mass change of burning iron wool. #chemed #scied @gochemistryvids

Cómic de

Reacciones químicas y colores

Enlaza con química y fuegos artificales y reacciones químicas vistosas

El caso del papel es algo que se puede asociar a método científico
Why Do Book Pages Turn Yellow Over Time? -

Most paper is made from wood, which largely consists of cellulose and a natural wood component called lignin that gives land plant cell walls their rigidity and makes wood stiff and strong. Cellulose — a colorless substance — is remarkably good at reflecting light, which means we perceive it as being white. This is why paper — including the pages of everything from sheet music to dictionaries — is usually white. Why Is Cow’s Milk White?
But when lignin is exposed to light and the surrounding air, its molecular structure changes. Lignin is a polymer, meaning it’s built from batches of the same molecular unit bonded together. In the case of lignin, those repeating units are alcohols consisting of oxygen and hydrogen with a smattering of carbon atoms thrown in, Richardson said.

The Chemistry of Paper Preservation: Part 2. The Yellowing of Paper and Conservation Bleaching -

Reacciones químicas y olores

A veces el olor se debe a presencia de sustancias volátiles, no a reacciones que las produzcan What Causes the Smell of New & Old Books? -