By examining electron domain geometry, one can determine that the ammonia molecule (NH_(3)) has one sp^2 orbital. two sp^2 orbitals three sp^3 orbitals four sp^3 orbitals

To domain geometry of the ammonia molecule (NH₃), we need to consider the number of electron domains (regions of electron density) around the central atom, which in this case is nitrogen.<br /><br />1. **Count the electron domains:**<br /> - Nitrogen has 5 valence electrons.<br /> - It forms three single bonds with three hydrogen atoms.<br /> - This leaves one lone pair of electrons on the nitrogen atom.<br /><br />So, there are a total of 4 electron domains (3 bonding pairs + 1 lone pair).<br /><br />2. **Determine the electron domain geometry:**<br /> - Four electron domains around a central atom typically adopt a tetrahedral arrangement to minimize electron-electron repulsion.<br /><br />3. **Identify the hybridization:**<br /> - A tetrahedral arrangement corresponds to \( sp^3 \) hybridization.<br /><br />Therefore, the nitrogen atom in the ammonia molecule (NH₃) uses four \( sp^3 \) orbitals to form the four electron domains.<br /><br />The correct answer is:<br />four \( sp^3 \) orbitals