Counting Atoms

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What is an atom?

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An atom is the smallest unit of matter that retains the properties of an element. It consists of a nucleus made of protons and neutrons, surrounded by electrons.

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What is a chemical formula?

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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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How do you count atoms in a chemical formula?

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To count atoms in a chemical formula, identify the elements and their respective subscripts. If an element has no subscript, it is assumed to be 1. Multiply the subscripts by any coefficients in front of the formula.

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What does a subscript in a chemical formula indicate?

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A subscript indicates the number of atoms of the element that are present in the molecule. For example, in H2O, the '2' indicates there are two hydrogen atoms.

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What does a coefficient in a chemical formula indicate?

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A coefficient indicates the number of molecules or formula units of a substance. For example, in 3H2O, the '3' means there are three water molecules.

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How many atoms of Fluorine (F) are in 3BeF2?

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There are 6 atoms of Fluorine in 3BeF2.

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How many atoms of Bromine (Br) are in 3KBr?

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There are 3 atoms of Bromine in 3KBr.

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How many atoms of Chlorine (Cl) are in 2B(ClO3)3?

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There are 6 atoms of Chlorine in 2B(ClO3)3.

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How many atoms of Sulfur are in 3PbSO4?

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There are 3 atoms of Sulfur in 3PbSO4.

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How many atoms of Oxygen are in 2Al(HSO4)3?

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There are 24 atoms of Oxygen in 2Al(HSO4)3.