There isn't a specific symbol for acid rain itself.

However, there are symbols used to represent the chemicals that cause acid rain, which are primarily sulfur dioxide (SO₂) and nitrogen oxides (NOx).

Here are the chemical symbols for those:

* SO₂: Sulfur dioxide

* NOx: Nitrogen oxides (this is a general term, specific compounds include NO, NO₂, etc.)

You might also see symbols representing pH, which is the measure of acidity. A lower pH indicates higher acidity.

It's important to remember that acid rain isn't a specific substance with its own symbol, but rather a phenomenon caused by the presence of acidic compounds in the atmosphere.