The answers this question is A.
The correct answer is 12.2% BaO.
The solution is found by dividing the mass of the BaO, which is 25.8 grams, by the total mass of the solution, which is 212 grams, then multiplying it by 100 to get the percentage:
If earth didn't rotate the global winds would stay on the same speed of rate because the wind isn't moving without rotation in the earths axis.
The moles of any substance are equal to the substance's mass divided by its molar mass. Therefore, in order to calculate the moles of copper, you would divide the reacted mass by 63.55