Axions are theoretical subatomic particles widely thought to be the constituents of dark matter.

Just like the scientists searching for the origin of dark matter in superconducting cavities, the @nytimes.com cannot find them in the Spelling Bee either.

cationization is the process of adding positive charge to a substance

@nytimes Spelling Bee must be on Spring Break and forget its chemistry vocabulary

an exciton is a bound electron-hole pair lying within the bandgap of a material

@nytimes Spelling Bee should register for intro condensed matter physics this semester