Walker, Sally M

Describes the physical characteristics, behavior, life cycle, and endangered status of rays.

Introduces these aquatic mammals by describing their physical characteristics, life cycle, behavior, relations with humans, and threats to their survival.

Describes the physical characteristics, life cycle, behavior, and conservation of rhinos.

Examines how electricity is produced and outlines the ways it can be used, from powering appliances to making objects stick together. Contains instructions for simple activities and includes full-color photographs, a glossary, and further reading sources.

Examines the physical features, processes, and many different species of plants and animals that make up the ecosystem of the largest estuary in the United States, the Chesapeake Bay.

Presents an introduction to matter, in simple text with illustrations, providing information on what it is and how it behaves in the world around us.

Describes the physical characteristics, life cycle, and behavior of sea horse as well as efforts to protect them.

Explains the forces inside the earth that make underground rocks move, causing landslides, fires, tsunamis, and other destructive effects of earthquakes.

An introduction to the physics of magnetism, which discusses the magnetic poles, explains how magnets work, and introduces magnetic materials.

An introduction to magnetism that explains what it is, what materials are magnetic, how magnets work, what magnetic poles are, and what the different types of magnets are.