1. Identify the Symbols:
* Each chemical formula uses symbols to represent different elements. For example:
* H stands for hydrogen
* O stands for oxygen
* Na stands for sodium
* Cl stands for chlorine
2. Count the Different Symbols:
* Look for different symbol combinations. Each unique symbol represents a different element.
3. Consider Subscripts:
* Subscripts, the small numbers written below and to the right of an element's symbol, indicate the number of atoms of that element in the compound.
* If there is no subscript, it is understood to be 1.
Example:
* H₂O (water)
* This formula has two elements: hydrogen (H) and oxygen (O).
* There are two hydrogen atoms (H₂) and one oxygen atom (O).
Let's try another:
* Na₂CO₃ (sodium carbonate)
* This formula has three elements: sodium (Na), carbon (C), and oxygen (O).
* There are two sodium atoms (Na₂), one carbon atom (C), and three oxygen atoms (O₃).
Important Note:
* When counting elements, you are counting the *types* of elements, not the total number of atoms in the molecule.
