Introduces the characteristics of sound, vibrations, and hearing, and discusses the ways in which sound can differ under different circumstances, echoes, music, and sound transmission.
Introduces the three states of matter and discusses how material objects can change and how such natural materials as wood can become such manufactured articles as paper.
Describes the process of how thunderstorms can form. Also includes explanations of downdrafts, storm cells, supercells, electric energy, thunder, lightning, squall lines, hail, and wind bursts.
Presents an introduction to the various types of grasslands, the different animals and plants that live in them, and the reasons for the overall reduction of grasslands in the world today.
Provides an introduction to stars, and explains what they are made of, along with their shapes and colors. Also describes constellations, and includes activity.
Describes how a compost heap works, what it needs to work well, and what plants, insects, and bacteria help to break down the organic refuse found in one.
Describes how wind and water erode the Earth's surface, forming different landscapes, and explains how people have adapted farming practices to prevent erosion.
