This exciting title introduces readers to the concept of a wave and the patterns and properties common to both light and sound waves. Clear text and detailed diagrams combine to demonstrate the cause-and-effect relationships involved in the properties of amplitude, wavelength, and frequency. A link to interactive activities online plus an activity in the book allows readers to explore key concepts close up by creating their own wave models.

In this fascinating title, readers explore how light and sound waves transfer information. From telescopes that extend our sense of sight to satellites that help us communicate across large distances, patterns of waves transfer information in many ways.

Viruses are contagious. They can be passed from person to person. They can also be passed to a person by an animal. Discover more in How Does a Virus Spread?, part of the Understanding Viruses series.

A virus is a type of germ so small that it can only be seen with a microscope. Viruses were discovered in the late 1880s. Discover more in What Is a Virus?, part of the Understanding Viruses series.

No one knows for sure where polio came from or when the first case took place. It has likely been around for thousands of years. Find out more in Polio, one of the titles in the International Outbreaks series.

A pandemic develops when a disease spreads across a country, continent, or around the world. Discover more in What Is a Pandemic?, part of the Understanding Viruses series.

People who feel unwell should try to avoid others. This helps stop the spread of the virus. The more contact people have with an infected person, the faster a virus spreads. Discover more in Staying Safe from Viruses, part of the Understanding Viruses series.

Measles has been around for hundreds of years. Settlers likely brought this disease to the Americas in the 1600s. Find out more in Measles, one of the titles in the International Outbreaks series.

The Ebola virus was first discovered in 1976 in Central Africa. The disease was named after the Ebola River, which flows near the region where Ebola was discovered. Find out more in Ebola, one of the titles in the International Outbreaks series.

Mountains are alpine biomes, which are home to an intriguing number of plants and animals. Some mountain animals, such as the yak, have been adapted for agriculture by humans. This intriguing book soars to new heights with simple-to-understand maps and detailed facts about an often-overlooked biome.