SIH3 lewis dot structure
The Correct Answer and Explanation is :
To draw the Lewis structure for SiH₃ (Silane), follow these steps:
Step 1: Count the Valence Electrons
- Silicon (Si): Silicon is in Group 14 of the periodic table, so it has 4 valence electrons.
- Hydrogen (H): Hydrogen is in Group 1, so each hydrogen atom has 1 valence electron.
- Therefore, the total number of valence electrons in SiH₃ is: [
4 \, (\text{from Si}) + 3 \times 1 \, (\text{from H}) = 7 \, \text{valence electrons}
]
Step 2: Arrange the Atoms
- Silicon (Si) is less electronegative than hydrogen (H), so it will be the central atom.
- Hydrogen atoms will be placed around the silicon atom.
Step 3: Form Bonds
- Place single bonds between the silicon atom and each of the three hydrogen atoms. Each single bond requires 2 electrons, so 3 bonds use up 6 electrons (3 × 2 = 6).
Step 4: Distribute Remaining Electrons
- After forming the bonds, 1 electron remains (7 total electrons – 6 electrons used in bonding).
- This remaining electron goes as a lone pair on the silicon atom. However, silicon typically prefers to form 4 bonds to fulfill the octet rule.
Step 5: Verify the Octet Rule
- Silicon can accommodate more than 8 electrons in its valence shell because it is in Period 3 of the periodic table. It can comfortably form 4 bonds and still fulfill its valence requirements.
- Since SiH₃ only has 7 electrons in total and each hydrogen has a complete duet, Si does not have an incomplete octet in this case.
Final Lewis Structure:
- Si is at the center with 3 single bonds to the three hydrogen atoms.
- There are no lone pairs on silicon in this structure.
This structure represents the molecule silane (SiH₃), where silicon is bonded to three hydrogens via single bonds.
Explanation:
In SiH₃, the silicon atom follows the bonding rule of filling its valence shell with electrons, typically forming four bonds. Hydrogen atoms, having only one electron, will always form one bond to fulfill their duet (two electrons). The structure represents a molecule with a trigonal geometry around the silicon atom, with bond angles close to 120 degrees.