Counting Atoms

Front

What are coefficients in a chemical equation?

Back

Coefficients are the numbers placed before the compounds in a chemical equation that indicate the number of molecules or moles of that substance involved in the reaction.

Front

What is a compound?

Back

A compound is a substance formed when two or more different elements are chemically bonded together, such as CO2 (carbon dioxide).

Front

Identify the reactants in the equation: 2H2 + O2 -> 2H2O.

Back

The reactants are 2H2 and O2.

Front

What does it mean for a chemical equation to be balanced?

Back

A balanced chemical equation has the same number of each type of atom on both sides of the equation, indicating that mass is conserved during the reaction.

Front

What is an element?

Back

An element is a pure substance that cannot be broken down into simpler substances by chemical means.

Front

What is the difference between a coefficient and a subscript in a chemical formula?

Back

A coefficient indicates the number of molecules, while a subscript indicates the number of atoms of an element in a molecule.

Front

Give an example of a balanced chemical equation.

Back

2Na + 2H2O -> 2NaOH + H2 is a balanced equation.

Front

What is the significance of subscripts in a chemical formula?

Back

Subscripts indicate the number of atoms of each element in a molecule, such as in H2O, where '2' indicates there are two hydrogen atoms.

Front

What is the formula for calculating the number of atoms in a molecule?

Back

To calculate the number of atoms, multiply the number of molecules by the sum of the subscripts in the chemical formula.

Front

What is a molecule?

Back

A molecule is a group of two or more atoms bonded together, which can be of the same or different elements.