The Lewis structure for sulfur tetrafluoride (SF4) can be drawn by following a systematic approach to represent the valence electrons around the atoms.
1. **Count the total valence electrons**: Sulfur (S) is in group 16 and has 6 valence electrons. Each fluorine (F) atom, also in group 17, has 7 valence electrons. Since there are four fluorine atoms, we have:
6 (from S) + 4 × 7 (from F) = 6 + 28 = 34 valence electrons in total.
2. **Determine the central atom**: Sulfur is less electronegative than fluorine, so it will be the central atom in the structure. The four fluorine atoms will surround the central sulfur atom.
3. **Connect the atoms with single bonds**: Connect each of the 4 fluorine atoms to sulfur with a single bond (which uses 2 electrons for each bond). This will use 8 out of the 34 total valence electrons, leaving us with 26 electrons.
4. **Distribute the remaining electrons**: Place the remaining electrons on the fluorine atoms to satisfy their octets (each needs 8 electrons). Since each fluorine is already involved in a bond with sulfur, we can place 6 more electrons (3 lone pairs) on each fluorine atom. This uses up all 26 remaining electrons (6 × 4 = 24, plus 8 used initially), leaving no extra electrons.
5. **Check for octets**: Each fluorine atom has 8 electrons around it, fulfilling the octet rule. Sulfur, however, is surrounded by 10 electrons (4 bonds), which is acceptable because it is in the third period and can exceed the octet rule.
Thus, the final Lewis structure looks as follows:
S – F
|
F – S – F
|
F
In conclusion, the Lewis structure for SF4 shows sulfur at the center with four single bonds to fluorine atoms, demonstrating how the valence electrons are distributed while adhering to the rules of covalent bonding and octet satisfaction where applicable.