1. How many moles is 4.25 x 1025 atoms of calcium?

Iknow the answer is a but i don't know why

Which of the following is true for the actual yield of a reaction? it is always calculated as a ratio. it is the yield from the excess reactant. it is the yield from the limiting reactant. it is always less than the theoretical yield.

In an investigation that uses the scientific method, which step immediately follows making a hypothesis? o summarizing the results o asking a question o making observations designing an experiment mark this and retum save and exit next submit