Counting Atoms - Subscripts

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What is a chemical formula?

Back

A chemical formula is a way of expressing the composition of a substance using symbols for its constituent elements and numbers to indicate the quantity of each element.

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What do subscripts in a chemical formula indicate?

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Subscripts indicate the number of atoms of the element present in a molecule. For example, in H2O, the '2' indicates there are two hydrogen atoms.

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How many elements are in the chemical formula HCl?

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There are 2 elements: Hydrogen (H) and Chlorine (Cl).

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How many different elements are present in H2COCH2?

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There are 3 different elements: Hydrogen (H), Carbon (C), and Oxygen (O).

Front

What is the correct formula for two sodium (Na), one sulfur (S), and four oxygen (O)?

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The correct formula is Na2SO4.

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How many elements are in the chemical formula C6H12O6?

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There are 3 elements: Carbon (C), Hydrogen (H), and Oxygen (O).

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How many chlorine atoms are in MgCl2?

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There are 2 chlorine atoms.

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What is the significance of the number in front of a chemical formula?

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The number in front of a chemical formula indicates how many molecules of that compound are present. For example, 2H2O means there are 2 molecules of water.

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What does it mean if a chemical formula has no subscript next to an element?

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If there is no subscript next to an element, it means there is one atom of that element in the molecule.

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How do you determine the total number of atoms in a chemical formula?

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To determine the total number of atoms, add up all the atoms represented by the elements and their subscripts in the formula.