Here's a breakdown:
* Atomic mass: The mass of a single atom of an element, typically measured in atomic mass units (amu). You can find these values on the periodic table.
* Chemical formula: A representation of a molecule or ion using chemical symbols and subscripts to indicate the number of each type of atom present.
Example:
Let's calculate the formula mass of water (H₂O):
1. Atomic masses:
* Hydrogen (H): 1.01 amu
* Oxygen (O): 16.00 amu
2. Formula: H₂O (meaning 2 hydrogen atoms and 1 oxygen atom)
3. Calculation: (2 * 1.01 amu) + (1 * 16.00 amu) = 18.02 amu
Therefore, the formula mass of water is 18.02 amu.
Key Points:
* Formula mass is also sometimes called molecular weight if the compound is a molecule.
* For ionic compounds, the term "formula mass" is preferred.
* Formula mass is used to calculate the mass of a specific number of molecules or ions.
