La naturaleza de la materia (The Nature of Matter)

Introduce students to immigration in America in the 1800s, and how it affected the United States. With this Spanish-translated book, readers will discover topics such as Ellis Island, Angel Island, and assimilation. Primary source images, fascinating facts, a glossary, and other features keep students engaged and help them better understand the social studies content.

Read Along or Enhanced eBook: Take a journey into the wild world of reptiles and amphibians! Readers will learn about crocodiles, lizards, snakes, tortoises, and salamanders. Featuring a glossary, index, colorful images and charts, intriguing facts, and clear, informative text, readers will be sure to be enthralled as they move through this engaging, Spanish-translated book.

Equality is a contentious issue in our society today. This is why it's important for students to be given information related to equality so they can come to reasonable conclusions of their own. Using age-appropriate language, this book discusses equality in a number of different forms and touches upon why equality is so important in a democracy. The text also explores how extreme equality, like most extremes, could be a bad and unrealistic idea. Readers will gain enough information to understand and think about this complex idea for themselves.

Imagine traveling at half the speed of a jet plane without ever leaving the ground! Students will discover the technology that makes such speeds possible, from special tracks and safety precautions to aerodynamically designed trains. What are the limits to the speed of trains? What imposes those limits? Students also will read about the future of passenger train travel, from flying trains to trains that use huge magnets to levitate inches or centimeters off the track. Some trains safely reach speeds of more than 200 mph!

A su paso por Saturno, las sondas Voyager tomaron, en los años 80 del siglo pasado, numerosas fotografías de sus anillos. Aquellas imágenes dieron pie, poco más tarde, a un extravagante experimento. Tras reproducir con suma precisión el diseño de los anillos en forma de surcos sobre un disco de vinilo, la audición desveló por sorpresa, en medio de una sucesión de frecuencias sin sentido, un fragmento de la Ofrenda musical, una de las composiciones más enigmáticas y esotéricas de Johann Sebastian Bach. Este sorprendente resultado podría interpretarse como un atisbo, singular y...

Got a fan of snakes, lizards, and turtles? Dig into this beginner's guide to reptiles from Cathryn and John Sill, creators of the award-winning About... series. Author and educator Cathryn Sill explains in simple language the basic characteristics that all reptiles share, while offering a look at many of the animals that fall into this diverse category, including ever-popular lizards, snakes, and turtles. The beautifully detailed paintings of noted wildlife illustrator John Sill depict reptiles in their habitats and highlight their unique aspects. An afterword provides more detail on each...