1. In the Gizmo, drag the apple onto the Scale. The scale measures mass. Mass is the amount of matter, or "stuff," in an object.
What is the apple's mass?
(Note: "g" stands for grams.)

Biomass can be used to generate electricity. biomass relies heavily on agricultural crops. plants release carbon dioxide and water in combustion. plants use photosynthesis to originally generate the energy that is needed. the chemical energy of these plants all started with what energy source?

What was the land like over 500 million years ago? what was under the sea?

During the winter, this species of fox has white fur, but in the summer, it has brown fur. what environmental change may have lead to this fox's fur color? snow cover increase in sun's brightness volcanic eruption global warming