Which of the following do NOT describe an element? 1. A mixture of different chemicals
2. Represented by a symbol that contains one uppercase letter
3. Represented by a symbol that can contain a second uppercase
letter
4. Represented by a symbol that can contain a lower case letter
5. A pure substance
6. Can be identified using the periodic table

Look at the following answer choices and determine which belongs in the both category. testable, can be disproven explains natural phenomena, has evidence to support it prediction, tentative, one or more scientists working together well established, many different scientists working independently, highly reliable

Construct at least two possible hypotheses for the student’s experiment.

The image shows the evolution of a species of fish. a few fish from a population developed different social behaviors and evolved into different species. two fish according to the image, the fish underwent . the new species of fish had mating seasons that were different from that of the original fish. because of the differences in mating seasons, the fish underwent reproductive isolation. this mode of isolation would be .