1. Chemical Formulas: This is the most common shorthand for compounds. It uses element symbols and subscripts to indicate the number of each atom in a molecule.
* Example: H₂O (water)
2. Molecular Formula: This is a specific type of chemical formula that shows the exact number and type of atoms in a molecule.
* Example: C₆H₁₂O₆ (glucose)
3. Empirical Formula: This is another type of chemical formula that shows the simplest whole-number ratio of atoms in a compound.
* Example: CH₂O (simplest form of glucose)
4. Structural Formula: This uses lines and symbols to represent the arrangement of atoms within a molecule.
* Example:
```
H
|
H - C - H
|
H
``` (methane)
5. Condensed Structural Formula: This is a more compact form of the structural formula, often used to simplify long chains.
* Example: CH₃CH₂CH₃ (propane)
6. Line-Angle Formula: This uses lines to represent bonds and assumes each corner or end of a line represents a carbon atom.
* Example:
```
C - C - C
``` (propane)
The best shorthand to use depends on what you want to emphasize.
* Chemical formulas are great for showing the composition of a compound.
* Structural formulas are useful for visualizing the arrangement of atoms.
* Condensed structural formulas are good for showing the connectivity of atoms in a compact way.
It's also worth noting that there are shorthand notations for specific functional groups or parts of molecules. For example, "Ph" is often used to represent a phenyl group (C₆H₅).