what are the three assumption when adding of oxide percentage found in all the elements add up to 128% in the calculation of elements because most elements bound to oxygen in the form of silicate. The elements are silicon, aluminum, iron calcium magnesium sodium, potassium and titanium have different weight of elements in crust and different weight of oxide in the crust
1. The assumption that the oxide percentages add up to 128% accounts for the fact that most elements are bound to oxygen in the form of silicate minerals in the Earth's crust. This means that the total weight of oxides of the elements is higher than 100% due to the presence of oxygen in multiple mineral structures.
2. The assumption also considers the variability in the weight of elements in the Earth's crust. Different elements like silicon, aluminum, iron, calcium, magnesium, sodium, potassium, and titanium have varying abundances in the Earth's crust, which influences the total weight of oxides when combined.
3. Finally, the assumption takes into account the difference in the weight of oxides for each element in the crust. Each element will have a unique ratio of oxide weight to elemental weight, leading to the overall total percentage of oxides exceeding 100% in the calculation.