Question

1. write the simple lewis - dot structure for each of the following atoms. a. mg (z = 12) b. br (z = 35) c. s (z = 16) d. si (z = 14) 12. write a lewis - dot structure for each of the following simple molecules. show all bonding valence electrons pairs as lines and all nonbonding valence electron pairs as dots. a. h2s b. sif4 c. c2h4 d. c3h8

Explanation:

Step1: Determine valence electrons

For 11 - a. Mg (Z = 12), Mg has 2 valence electrons. The Lewis - Dot structure is Mg with 2 dots around it.
For 11 - b. Br (Z = 35), Br has 7 valence electrons. The Lewis - Dot structure is Br with 7 dots around it.
For 11 - c. S (Z = 16), S has 6 valence electrons. The Lewis - Dot structure is S with 6 dots around it.
For 11 - d. Si (Z = 14), Si has 4 valence electrons. The Lewis - Dot structure is Si with 4 dots around it.

Step2: Determine valence electrons for molecules in 12

For 12 - a. H₂S: H has 1 valence electron and S has 6 valence electrons. Total valence electrons = 2×1 + 6=8. The Lewis - Dot structure has S in the center with 2 single bonds to H and 2 non - bonding electron pairs on S.
For 12 - b. SiF₄: Si has 4 valence electrons and F has 7 valence electrons. Total valence electrons = 4+4×7 = 32. Si is in the center with 4 single bonds to F, and each F has 3 non - bonding electron pairs.
For 12 - c. C₂H₄: C has 4 valence electrons and H has 1 valence electron. Total valence electrons = 2×4+4×1 = 12. There is a double bond between the two C atoms and each C has 2 single bonds to H atoms.
For 12 - d. C₃H₈: C has 4 valence electrons and H has 1 valence electron. Total valence electrons = 3×4 + 8×1=20. The three C atoms are in a chain, with single bonds between C atoms and single bonds from each C to H atoms.

Answer:

11 - a. Mg with 2 dots around it
11 - b. Br with 7 dots around it
11 - c. S with 6 dots around it
11 - d. Si with 4 dots around it
12 - a. S in the center with 2 single bonds to H and 2 non - bonding electron pairs on S
12 - b. Si in the center with 4 single bonds to F, and each F has 3 non - bonding electron pairs
12 - c. Double bond between the two C atoms and each C has 2 single bonds to H atoms
12 - d. Three C atoms in a chain, with single bonds between C atoms and single bonds from each C to H atoms