The Lewis formula for fluoromethane, CH3F, has
A) four lone pairs.
B) four bonding pairs,
C) two bonding pairs and two lone pairs.
D) three bonding pairs and one lone pair.
E) four bonding pairs and three lone pairs.
The Correct Answer and Explanation is :
The correct answer is B) four bonding pairs.
Explanation:
The Lewis structure of fluoromethane (CH₃F) represents the bonding between the atoms in the molecule and the placement of electrons in lone pairs and bonding pairs.
To start, the molecule consists of carbon (C), hydrogen (H), and fluorine (F) atoms:
- Carbon (C) is the central atom in this molecule.
- Three hydrogen (H) atoms are bonded to carbon.
- One fluorine (F) atom is also bonded to carbon.
Step-by-step breakdown:
- Valence Electrons:
- Carbon (C) has 4 valence electrons.
- Each hydrogen (H) atom has 1 valence electron.
- Fluorine (F) has 7 valence electrons. So, the total number of valence electrons is:
[
4 \, (\text{from C}) + 1 \times 3 \, (\text{from H}) + 7 \, (\text{from F}) = 14 \, \text{electrons}.
]
- Bond Formation:
- Carbon forms single bonds with the three hydrogen atoms, using 6 electrons (since each C-H bond uses 2 electrons).
- Carbon also forms a single bond with fluorine, using 2 more electrons.
- Electron Pair Distribution:
After forming the C-H and C-F bonds, the remaining electrons are placed as lone pairs:
- Fluorine (F) has 6 electrons left after forming the bond with carbon, and these electrons will be placed as 3 lone pairs on fluorine.
- Carbon (C) does not have any lone pairs and uses all its valence electrons to form bonds.
Therefore, there are four bonding pairs:
- 3 C-H bonds (each with a bonding pair of electrons).
- 1 C-F bond (with a bonding pair of electrons).
The rest of the electrons are placed as lone pairs on fluorine, but they do not count as bonding pairs.
This structure confirms the correct answer is B) four bonding pairs.
Now, I will generate an image of the Lewis structure for fluoromethane.
Here is the image showing the Lewis structure of fluoromethane (CH₃F). It illustrates the four bonding pairs between carbon, hydrogen, and fluorine atoms, as well as the lone pairs on fluorine. Let me know if you need further clarifications!