| an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle. |
| a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question. |
| Kirchhoff (kîr'kôf') Pronunciation Key
German chemist who with Robert Bunsen discovered the elements cesium and rubidium. He also investigated the solar spectrum and researched electrical circuits and the flow of currents. His electromagnetic theory of diffraction is still the most commonly used in optics. |