Los estados de la materia — Los líquidos

The scientific method lists important steps in the process of conducting scientific study and research. With detailed images and fascinating sidebars, this nonfiction book explores the scientific method and scientific practices in depth, and introduces students to new concepts, vocabulary terms, and STEM topics. Aligned to state and national standards, the leveled text supports students reading at above-, below-, and on-grade level. The fun lab activity encourages students to think like scientists. Keep students engaged in learning with this Spanish book.

When people go to sleep, bats are just waking up. While young readers may recognize the image of bats in the night skies, where they live may be less familiar. This title takes readers inside bat roosts to uncover the fascinating facts about this creature. Readers will learn the basics of bat roosts—in caves and beyond—and how they help bats survive in the wild. The text also looks at bat’s appearance, behavior, and the crucial role they play in nature’s ecosystems—topics covered in most elementary science curricula. Diagrams, fact boxes, colorful images encourage learning.

For thousands of years, militaries around the world were limited to male soldiers. However, throughout history, brave women have stepped out of the background and onto the battlefield. This biographical text covers the important women who’ve broken ground in the military. Famous historical figures such as Joan of Arc, Clara Barton, and Florence Nightingale are covered in depth, while the stories of modern-day heroes are presented to show how women are still affecting change on the front lines. A comprehensive timeline, fact boxes, and historical and modern images complete this...

¿Y si el universo no pesara nada y la materia no existiera realmente? Lo que parecería ser una duda legítima para un erudito místico de los Vedas Indios es, en cambio, un resultado embarazoso de la aplicación de la Relatividad Restringida a las observaciones obtenidas por un grupo de astrofísicos, que han medido la radiación cósmica de fondo de nuestro universo. En los albores del nuevo milenio, el satélite WMAP, más allá de proporcionarnos una medida del cosmos, nunca antes obtenida, ha creado bastantes quebraderos de cabeza respecto al concepto de universo, en el que todavía hoy ...