First, we divide the mass fraction of each element by their corresponding molar mass:
0.52 / 32.1 = 0.0162
0.285 / 16 = 0.0184
Next, we simply divide the values that we get:
0.0184/0.0162 = 1.14
So, the there are 1.14 times more oxygen atoms than sulfur atoms in the Earth's crust.
