Conservación de la masa (Conservation of Mass)

Light can travel faster than anything else in the universe. But what exactly is light, and where does it come from? This nonfiction Spanish book teaches students all about light, and introduces them to important scientific concepts and vocabulary terms like infrared, ultraviolet, photos, and visible spectrum. The intriguing images, detailed diagrams, and stimulating sidebars will keep students connected to the text. The fun lab activity provides a real-world learning experience that supports STEM instruction. Aligned to state and national standards, the leveled text supports differentiation....

"Provides clues about an owl's physical characteristics, behaviors, and habitats in a guessing game format."--From source other than the Library of Congress

During the American Civil War, the United States was on the brink of falling apart irrevocably. As states seceded and brother turned against brother, hope for reconciliation was dim. This conflict, an essential topic of the social studies curriculum, is skillfully presented from its origins in the Southern slave-trade economy to bloody battles and, later, Reconstruction. Striking photographs and artwork of integral events and people will resonate with readers, while interesting sidebar information gives them more to reflect on about this terrible war and the lessons it taught us.

Memorial Day is an important and special holiday, but some people forget why we celebrate it. On the last Monday of May each year, people around the country gather and remember the men and women who've died while serving in the U.S. military. This educational book encourages readers to reflect on the sacrifices military personnel make to protect our country. This book also touches upon the more lighthearted side of the holiday and the different types of celebrations that people have each year. Featuring full-color photographs and accessible text, this book is sure to engage beginning readers.

La historia de la ciencia en la Edad Media es, hasta el siglo X, la del mantenimiento precario de los escasos saberes de la Antigüedad clásica que habían sobrevivido en occidente. A partir de entonces, la traducción del árabe de las obras de autores griegos fue la tarea fundamental. En el siglo XIII aparecen los primeros matemáticos medievales realmente creadores - Fibonacci, Jordano Nemorario y Nicolás de Oresme, entre otros. Al estudio de la obra de estos científicos y la de sus precursores está dedicado este libro.