a muddy stream quickly flows downhill. When it reaches a flatter area, the stream moves more slowly, and the water clears. Explain why the stream changes appearance.

The first element on the periodic table of elements is carbon. a. true b. false

Match the following items. 1. high-intensity bundle of energy being emitted from some decaying nuclei gamma ray 2. particle radiating from the nucleus of some atoms beta particle 3. negative particle identical to an electron but radiating from a decaying nucleus alpha particle

How did planetesmals form planets? a. they broke apart into smaller chunks.b. they collided and stuck together.c. they cooled and pulled ice together.d. they began to rotate.