1164
There are four types of chemical bonds : covalent bonds , in which compounds share one or more electron ( s ) ; ionic bonds , in which a compound donates one or more electrons to another compound to produce ions ( cations and anions ) ; hydrogen bonds ; and Van der Waals force bonds .
 Van der Waals
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Van der Waals