In the compound P2O5, the ratio of phosphorous to oxygen is

The ratio of phosphorous to oxygen is 2:5

Explanation:

In a compound P2O5, the ratio of phosphorous to oxygen atoms is 2:5. Because there are two phosphorous atoms and five oxygen atoms. Both combined are called a P2O5.The elements of phosphorous and oxygen are added to P2O5. So P2O5 is called as phosphorous pentoxide. The element phosphorous will be added to oxygen and it will form a chemical reaction.This includes a change in the energy of  P2O5. So the new energy will be produced.                

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