Can replicators transmute elements?
Yes… sort of. There have been occasions on the show where some required element cannot be replicated. The Tech Manual talks about “quantum transformational manipulation”, so they can do some quantum twiddling to get new elements. However, it also says that the energy costs are high for all forms of replication, and that food, since it’s usually just different arrangements of the same basic things (water, proteins, lipids), is more practical to replicate from bulk matter than to store. In “Night Terrors” [TNG], when a certain substance is needed, Data says “We no longer have the power to reproduce complex elements in the replicator.” This is evidence for the above. ….
