This book introduces school-age children to the world of scientific experimentation. It includes 29 experiments related to the fields of light and sound, mass, actions and reactions, other forces, mechanical energy, and chemical reactions. Each experiment is structured to answer the four questions: What do we want to prove? What do we need? How do we do it? Why and what happened?

Jordi Mazón is a professor and researcher in the applied physics department at the Polytechnic University of Catalonia. He is the author of a dozen books, including 100 preguntas de física: ¿Por qué vuelan los aviones de papel, y por qué vuelan los de verdad? and Conocer las nubes. Raquel Gu is a cartoonist, an illustrator, and a translator. She is the author and illustrator of Pequeños Granujas and Tengo diabetes, ¿te lo cuento? and the illustrator of Mati y sus mateaventuras.