To draw the electron dot formula for sulfur tetrafluoride (SF4), we start by determining the number of valence electrons in the molecule. Sulfur (S) has 6 valence electrons and each fluorine (F) atom has 7 valence electrons. Since there are four fluorine atoms, we calculate the total valence electrons as follows:
- Valence electrons from sulfur: 6
- Valence electrons from fluorine: 4 x 7 = 28
- Total valence electrons = 6 + 28 = 34
Next, we place the sulfur atom in the center as the central atom and surround it with the four fluorine atoms. Each fluorine will form a single bond with sulfur, using 2 electrons per bond (4 bonds total). This uses up 8 of the 34 total valence electrons, leaving us with 26.
Each fluorine atom requires 6 more electrons to complete its octet, which can be represented as three pairs of dots around each fluorine atom. Thus, in the final diagram:
- The sulfur atom will have 4 bonding pairs of electrons (one pair for each S-F bond).
- Each fluorine atom will have 3 lone pairs of electrons.
The resulting electron dot formula for SF4 can be depicted as follows:
F F
: :
•S•
:
F F
In this representation, the dots (•) around sulfur indicate the bonding pairs with the fluorine atoms, and the colons (:) represent the lone pairs of electrons around each fluorine. This illustrates the molecular structure where sulfur is the central atom bonded to four fluorine atoms, resulting in the geometry characteristic of SF4.