Answer:
2.38x10²³ atoms oxygen
Explanation:
To solve this question we need to convert the mass of sand to moles using its molar mass (Molar mass SiO₂ = 60.08g/mol). Twice these moles are the moles of Oxygen and using Avogadro's number we can find the amount of atoms of Oxygen in the mixture:
Moles SiO₂:
11.87g * (1mol / 60.08g) = 0.1976moles SiO₂
Moles Oxygen:
0.1976moles SiO₂* 2 = 0.3951moles oxygen
Atoms oxygen:
0.3951moles oxygen * (6.022x10²³atoms / 1mol O₂) =
2.38x10²³ atoms oxygen
