The Lewis structure for carbon tetrabromide (CBr4) is a representation that shows how the valence electrons are arranged among the atoms in the molecule. To draw the Lewis structure, follow these steps:
- Determine the total number of valence electrons: Carbon has 4 valence electrons, and each bromine (Br) atom has 7 valence electrons. Since there are 4 bromine atoms, the total is 4 + (4 x 7) = 32 valence electrons.
- Place the carbon atom in the center because it is less electronegative than bromine. Surround it with the four bromine atoms.
- Connect each bromine atom to the carbon atom with a single bond. Each bond uses 2 electrons, so 4 bonds x 2 electrons = 8 electrons used.
- Subtract the bonding electrons from the total: 32 – 8 = 24 electrons remain.
- Distribute the remaining electrons: Place 6 electrons (3 lone pairs) around each bromine atom to satisfy their octet. This uses up all the remaining electrons: 4 x 6 = 24 electrons.
The final structure has the carbon atom in the center with four bromine atoms each connected by a single bond. Each bromine atom has three lone pairs of electrons. This configuration satisfies the octet rule for all the atoms involved, and thus, the Lewis structure for CBr4 is complete and stable.