Which of the following is correct when comparing reactants and products? a. reactants have more mass than products. b. products have more mass than reactants. c. pure substances making up reactants are different than those in products. d. pure substances making up reactants are the same as those in products.

Atypical human cell is approximately 12.00 μm in diameter and enclosed by a membrane that is 5.000 nm thick. (a) what is the volume of the cell including the membrane? (b) what is the volume of the cell membrane? (c) what percent of the total volume does its membrane occupy? to simplify the calculations, model the cell as a sphere. enter your answers using four significant figures.

Aristotle classified animals according to their a. habitat and mating behavior c. mating behavior and relatedness b. habitat and physical differences d. physical differences and mating behavior

What are the student's observations and inferences before he starts his investigation?