Katie Marsico 
Key Discoveries in Physical Science [PDF ebook] 

How did our knowledge of matter, gravity, and electricity develop over time? Who first studied these concepts and why? And who used those early findings to expand and even change our understanding? Readers will trace the history of key discoveries in physical science as they investigate timelines and gather key details from the text. In doing so, students will make connections between the work of various scientists and analyze the long-term effects of their discoveries.