Section 1
What is Matter? (Macro View)
Key Idea
Look around the rainforest. Everything you see—from the heavy jaguar to the water in the river, and even the invisible air filling the space between trees—is made of "stuff." Scientists call this physical stuff matter.
Two rules help us identify matter: it must have mass (weight) and it must take up space. Whether it is a living sloth or a non-living rock, if it takes up space and has mass, it is matter. This means the entire ecosystem is built from the same fundamental material.