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: Of the 14 patients , 5 ( 35 . 7 % ) had white matter abnormalities , 1 ( 7 . 1 % ) had putaminal hemorrhage , and 8 ( 57 . 1 % ) had normal findings on initial MR images .
### Output Text:
Of the 14 patients , 5 ( 35 . 7 % ) had white matter abnormalities , 1 ( 7 . 1 % ) had putaminal hemorrhage , and 8 ( 57 . 1 % ) had normal findings on initial MR images . 