During diffusion substances move from the denser medium (meaning where there is more of the substance) to less dense medium (meaning where there is less of the substance).
Answer: a very large number of objects
Explanation: Mole is the amount of objects and it has the usually Avogadro number of atoms, molecules, ions, etc in chemistry
Answer: I believe the correct answer would be A.
We know that when calculating percent yield, we use the equation:

Since the quantities that we are given in the question are equal, we can just directly divide them to find percent yield:

So now we know that the percent yield of the synthesis is 87.27%.
There are seven periods with eighteen columns in the periodic table.