A. He should add shells that are different colors, but the same size and type, to the tank and observe which shells the hermit crabs choose.
Durning an experiment you need to keep everything the same but only change the certain things based on your theory.
Such as how the student wanted to see if the color attracted the crab. If he had changed the size and type of the shell then the crab would have chosen the bigger one as they tend to grow into larger shells.
Truuuueeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
Humans and Apes evolved separately from monkeys. Hope this helps.
Answer:
Electrons are negatively charged particles of an atom. All the electrons of an atom create a negative charge that balances the positive charge of the protons. The nucleus, which is the dense core of the atom, contains both protons and neutrons. Electrons, though, are outside of the nucleus.
Hope this helps
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Explanation:
