1. CF₄:
- Carbon (C) has 4 valence electrons.
- Each Fluorine (F) has 7 valence electrons; 4 F atoms = 28 valence electrons.
- Total valence electrons = 4 + 28 = 32.
- Place C in center, bond each F to C with a single bond (using 8 electrons).
- Distribute remaining 24 electrons as 3 lone pairs on each F atom.
- All atoms have complete octets.
2. CH₄:
- Carbon (C) has 4 valence electrons.
- Each Hydrogen (H) has 1 valence electron; 4 H atoms = 4 valence electrons.
- Total valence electrons = 4 + 4 = 8.
- Place C in center, bond each H to C with a single bond.
- No lone pairs remain; all 8 electrons are used in bonds.
- Carbon has 8 electrons (4 bonds), each H has 2 electrons (1 bond).
3. CH₃F:
- Carbon (C) has 4 valence electrons.
- Three Hydrogens (H) contribute 3 valence electrons.
- Fluorine (F) has 7 valence electrons.
- Total valence electrons = 4 + 3 + 7 = 14.
- Place C in center, bond three H and one F to C with single bonds (using 8 electrons).
- Distribute remaining 6 electrons as 3 lone pairs on F.
- All atoms have complete octets (H has duet).
4. CH₂F₂:
- Carbon (C) has 4 valence electrons.
- Two Hydrogens (H) contribute 2 valence electrons.
- Two Fluorines (F) contribute 14 valence electrons (7 each).
- Total valence electrons = 4 + 2 + 14 = 20.
- Place C in center, bond two H and two F to C with single bonds (using 8 electrons).
- Distribute remaining 12 electrons as 3 lone pairs on each F.
- All atoms have complete octets (H has duet).
Parent Tip: Review the logic above to help your child master the concept of lewis dot structure practice worksheet.
