To discuss the orbital structures of the molecules NH₃, C₂H₂, and CO₂ based on hybridization, we will analyze each molecule step by step.
### Step 1: Analyze NH₃ (Ammonia)
1. **Determine the central atom**: In NH₃, nitrogen (N) is the central atom.
2. **Count the valence electrons**: Nitrogen has 5 valence electrons, and each hydrogen (H) has 1 valence electron. Thus, NH₃ has a total of 5 + (3 × 1) = 8 valence electrons.
3. **Identify the hybridization**: To form three bonds with hydrogen atoms, nitrogen undergoes sp³ hybridization. This involves the mixing of one s orbital and three p orbitals.
4. **Geometry**: The molecular geometry of NH₃ is trigonal pyramidal due to the presence of one lone pair on nitrogen, which pushes the hydrogen atoms down.
### Step 2: Analyze C₂H₂ (Ethyne)
1. **Identify the central atoms**: In C₂H₂, there are two carbon (C) atoms and two hydrogen (H) atoms.
2. **Count the valence electrons**: Each carbon has 4 valence electrons, and each hydrogen has 1. Thus, C₂H₂ has a total of (2 × 4) + (2 × 1) = 10 valence electrons.
3. **Determine the hybridization**: Each carbon atom in C₂H₂ undergoes sp hybridization. This involves the mixing of one s orbital and one p orbital, resulting in two sp hybrid orbitals.
4. **Geometry**: The molecular geometry is linear because the two carbon atoms are connected by a triple bond, and each carbon is bonded to one hydrogen atom.
### Step 3: Analyze CO₂ (Carbon Dioxide)
1. **Identify the central atom**: In CO₂, carbon (C) is the central atom with two oxygen (O) atoms on either side.
2. **Count the valence electrons**: Carbon has 4 valence electrons, and each oxygen has 6. Thus, CO₂ has a total of 4 + (2 × 6) = 16 valence electrons.
3. **Determine the hybridization**: The carbon atom in CO₂ undergoes sp hybridization. This involves the mixing of one s orbital and one p orbital, resulting in two sp hybrid orbitals.
4. **Geometry**: The molecular geometry is linear because carbon forms double bonds with each oxygen atom.
### Summary of Hybridization and Geometry
- **NH₃**: sp³ hybridization, trigonal pyramidal geometry.
- **C₂H₂**: sp hybridization, linear geometry.
- **CO₂**: sp hybridization, linear geometry.
