Welcome back to the wonderful world of chemistry. A world that, as you grow older, becomes more beautiful and more exciting. Have you ever wondered why the orange juice we drink has a sour taste? Why do we need to use the appropriate medicine depending on the type of insect that bites us? Why shouldn't we clean the marble in our house using just any liquid? How are the clay, glass, and ceramic objects we have in our home made? How can we make useful products for our daily life from petroleum? These are just some of the questions for which you will learn the answers in the chemistry of the 3rd grade of middle school. [...]

(from the author's preface)