8823
The presence of Si - H bonds and the morphology of the SiNWAs are found to be crucial to the occurrence of such catalytic activity .
 Chemical: Si; Chemical: H
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: Si, H 
Answer:
 Chemical: Si; Chemical: H