TOW (& Answer)...
The question this week was what is efflorescence? Efflorescence, to quote the source, “is the process in which a crystalline hydrated solid loses water of crystallization to the air. A powdery deposit is gradually formed.”
The question (& answer) were taken from p. 85 of The Facts on File Dictionary of Chemistry by John Daintith. The book was published by Checkmark Books in 1999.