Lone Pairs of Electrons on SF4, CF4, and XeF4

1. SF4 (Sulfur Tetrafluoride)
SF4 is a molecule that consists of a central sulfur atom bonded to four fluorine atoms. To determine the number of lone pairs of electrons on SF4, we need to consider its Lewis structure.

- The central sulfur atom has 6 valence electrons.
- Each fluorine atom contributes 7 valence electrons, giving us a total of 28 electrons.
- The single bond between sulfur and each fluorine atom accounts for 8 electrons (4 x 2).
- This leaves us with 20 electrons to distribute as lone pairs.

To minimize electron repulsion and achieve the most stable structure, we arrange the fluorine atoms around the sulfur atom in a trigonal bipyramidal geometry. This arrangement consists of three equatorial fluorine atoms in a plane and two axial fluorine atoms above and below the plane.

- The three equatorial fluorine atoms are bonded to sulfur through single bonds, accounting for 6 electrons.
- The remaining 14 electrons are distributed as three lone pairs, one on each equatorial fluorine atom.

Therefore, SF4 has 1 lone pair of electrons.

2. CF4 (Carbon Tetrafluoride)
CF4 is a molecule that consists of a central carbon atom bonded to four fluorine atoms. To determine the number of lone pairs of electrons on CF4, we again need to consider its Lewis structure.

- The central carbon atom has 4 valence electrons.
- Each fluorine atom contributes 7 valence electrons, giving us a total of 32 electrons.
- The single bond between carbon and each fluorine atom accounts for 8 electrons (4 x 2).

Since carbon does not have any lone pairs of electrons in its valence shell, CF4 has 0 lone pairs of electrons.

3. XeF4 (Xenon Tetrafluoride)
XeF4 is a molecule that consists of a central xenon atom bonded to four fluorine atoms. To determine the number of lone pairs of electrons on XeF4, we once again consider its Lewis structure.

- The central xenon atom has 8 valence electrons.
- Each fluorine atom contributes 7 valence electrons, giving us a total of 36 electrons.
- The single bond between xenon and each fluorine atom accounts for 8 electrons (4 x 2).

To minimize electron repulsion and achieve the most stable structure, we arrange the fluorine atoms around the xenon atom in a square planar geometry.

- The four fluorine atoms are bonded to xenon through single bonds, accounting for 8 electrons.
- This leaves us with 28 electrons to distribute as lone pairs.

Since xenon has a total of 8 valence electrons, it can accommodate two lone pairs. Therefore, XeF4 has 2 lone pairs of electrons.

Hence, the correct answer is option B - 1, 0, and 2 lone pairs of electrons for SF4, CF4, and XeF4, respectively.