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Why was the sample heated in step 5? describe the chemical principles involved in the reasoning behind this step?

Explain the source of radioactivity in uranium in earth’s crust by which it produces nuclear radiation

Which of the following is a feature of all cells? o a. all cells have a nucleus. o b. all cells have dna for at least part of their life cycle. het . o c. all cells are spheres. o d. all cells have a rigid cell wall.