The answer is the percent composition which is number 4. This is the percent by mass of each element existing in a compound. To compute for this, you need to find two things: the mass of just the element, and the molar mass of the entire compound. Afterwards, you take the molar mass of only the element and divide it by the molar mass of the entire compound, and multiply by 100%.
The percent composition by mass of each element in a compound can be calculated using its formula and the Periodic Table. This involves determining the molar mass of the compound and the mass of each element. Therefore, the chosen option is 4.
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