Can someone help me to answer this correctly, please, and explain it. Please answer these 3 short questions, I don't have more money to buy more questions. These 3 questions are different.

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A compound is found to contain 27.29% carbon and 72.71% oxygen by mass. What is the empirical formula for this compound? To answer the question, enter the elements in the order presented above. A compound is found to contain 26.94% nitrogen and 73.06% fluorine by mass. What is the empirical formula for this compound? To answer the question, enter the elements in the order presented above. A compound is found to contain 46.68% nitrogen and 53.32% oxygen by weight. What is the empirical formula for this compound? To answer the question, enter the elements in the order presented above