2512
The existence of ions has a negligible disturbance to the hydrogen bond structures and rotational mobility of water beyond the first ion solvation shells , which is suggested by the local hydrogen bond structures and the rotation times of water .
 Chemical: hydrogen; Chemical: hydrogen
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: hydrogen; Chemical: hydrogen