Which of the following best describes the Lewis dot structure for a neutral Si2 molecule?

• A. Each Si atom shares three pairs of electrons, forming a triple bond between the Si atoms.
• B. The Si atoms do not share any electrons and remain as separate atoms.
• C. Each Si atom shares one pair of electrons, forming a single bond between the Si atoms.
• D. Each Si atom shares two pairs of electrons, forming a double bond between the Si atoms.

Answer: (D)

Verified step by step guidance

1. Recall that a Lewis dot structure represents the valence electrons of atoms and how they are shared or paired to form bonds.
2. Determine the number of valence electrons for each silicon (Si) atom. Silicon is in group 14, so each Si atom has 4 valence electrons.
3. Consider how these valence electrons can be shared between two Si atoms to satisfy the octet rule, aiming for each atom to have 8 electrons around it.
4. Evaluate the possible bonding scenarios: single bond (sharing 1 pair), double bond (sharing 2 pairs), or triple bond (sharing 3 pairs) between the two Si atoms, and check which allows both atoms to complete their octet.
5. Conclude that sharing two pairs of electrons (a double bond) between the Si atoms allows each atom to achieve a full octet, making the Lewis structure with a double bond the best description for the neutral Si2 molecule.