Based on the clue 'challenging the election of calixtus in 217 hippol...', what is the answer?

Based on the clue 'chalk is a naturally occurring form of this compou...', what is the answer? Based on the clue 'chalk white arrows lead to this title shel silvers...', what is the answer? Based on the clue 'challah a type of this is served in a twisted form...', what is the answer? Based on the clue 'challenges someone to a demonstration of courage', what is the answer? Based on the clue 'chalti bhasa is the spoken form of this official l...', what is the answer? Based on the clue 'chalupas came in 3 flavor options supreme baja on...', what is the answer? Based on the clue 'chamber live an interactive addition to this scary...', what is the answer? Based on the clue 'chambers dictionary describes this cream filled pa...', what is the answer?