In chemical reactions, the reactants are consumed to create the products, and (assuming this is a normal chemical reaction) the reactants are located to the left of the arrow while the products are located to the right of the arrow. So in this case, Fe would be a reactant, S would be a reactant, and the FeS would be a product.
Answer: An electron will jump to a higher energy level when excited by an external energy gain such as a large heat increase or the presence of an electrical field, or collision with another electron.
The sample contains 38.7 g of Ca, 19.9 g of P, and 41.2 g of O as the proportions show.
Then we can calculate the number of moles of each component (n = m/atomic mass).
The number of moles of Ca = 38.7/40.078 = 0.96 mol.
The number of moles of P = 19.9/30.97 = 0.64 mol.
The number of moles of O = 41.2/15.99 = 2.75 mol.
Now, we can get the molar ratios of different components (Ca, P, and O) in the sample by dividing the number of moles of each component by the lower number of moles, that we should divide the number of moles by (0.64).
