2467
While most high and medium oxidation state ( O . S . >= 3 ) metal and non - metal fluorides and oxide fluorides are strong Lewis acids , exploration of their coordination chemistry with neutral ligands has been limited and mostly non - systematic .
 Chemical: metal and non - metal fluorides; Chemical: oxide; Chemical: fluorides; Chemical: Lewis acids
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: metal and non - metal fluorides; Chemical: oxide; Chemical: fluorides; Chemical: Lewis acids