In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: The incidence of ventricular arrhythmias ( p = 0 . 004 ) and seizures ( p = 0 . 03 ) in the CaCl2 group was higher than the other groups .
### Output Text:
The incidence of ventricular arrhythmias ( p = 0 . 004 ) and seizures ( p = 0 . 03 ) in the <span class="chemical">CaCl2</span> group was higher than the other groups . 