D.) There must be an equal number of atoms of each element on both sides of the equation
The mass of a 0.513 mol of Al2O3 is 52.33g.
HOW TO CALCULATE MASS:
The mass of a substance can be calculated by multiplying the molar mass of the substance by its number of moles. That is;
mass of Al2O3 = no. of moles of Al2O3 × molar mass of Al2O3
According to this question, there are 0.513 moles of Al2O3.
Mass of Al2O3 = 0.513 × 102
Mass of Al2O3 = 52.33g
Therefore, the mass of a 0.513 mol of Al2O3 is 52.33g.
Learn more about mass calculations at: brainly.com/question/8101390?referrer=searchResults
As far as I know, the answer is B (breaking a rock)