19180
Looking at their absorption spectra , these systems with aluminum and gallium may also have , as in the case of boron , promising photochemical properties .
 Chemical: aluminum; Chemical: gallium; Chemical: boron
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: aluminum; Chemical: gallium; Chemical: boron