What mass of water must be used to prepare a solution of 25.5 g of CaCl2 dissolved in water if the mole fraction. please help me

Why do scientists look for patterns in the world? a. patterns can explain observations. b. patterns never change, no matter what. c. patterns are easy for scientists to detect. d. patterns are all the same, through all time.

Carbon-14 undergoes radioactive decay in the reaction above. determine the type of radiation emitted in this reaction and describe what is happening to the nucleus during this reaction.

What relationship exists between an enzyme and a catalyst?