What does a number in front of a molecular formula stand for

Explanation:

The small number behind each element symbol designates the number of atoms of each element in a chemical formula. If there is no number, it is assumed there is only one of those elements. A large number designates how many units there are of that compound.

Element's number of atoms in a chemical formula

Explanation:

The small number behind each element symbol indicates each element's number of atoms in a chemical formula. If there is no number, it is assumed there is only one of these elements. A huge numeral in front of a compound designates whereby many units there are of that compound.

the sugar-phosphate backbone forms the structural framework of nucleic acids, including dna and rna. this backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.

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