Which of the following sets correctly represents an electron-deficient, an electron-precise, and an electron-rich molecule respectively?

Step-by-step solution

Electron-deficient molecules do not have a complete octet or lack sufficient electrons for normal 2c-2e bonds. B ₂ H ₆ is a group 13 hydride and is electron-deficient. Electron-precise molecules have exactly 8 valence electrons around the central atom with no lone pairs. CH ₄ is a group 14 hydride and is electron-precise. Electron-rich molecules have a complete octet with one or more lone pairs on the central atom. NH ₃ is a group 15 hydride with one lone pair, making it electron-rich. Thus, the correct sequence is