Question

1. the central selenium atom in selenium hexafluo - ride forms an expanded octet. how many electron pairs surround the central se atom? a. 4 b. 5 c. 6 d. 7 11. which compound does not have a bent molecular shape? a. beh₂ c. h₂o b. h₂s d. seh₂ 12. ccl₄ is a nonpolar molecule that boils at low temperatures. this is because only ______ exist between ccl₄ molecules. a. hydrogen bonds c. dipole - dipole forces b. metallic bonds d. london/dispersion forces 13. a nonpolar covalent bond is the result of a. electrostatic attractions between the atoms in the bond. b. unequal sharing of electrons by the atoms in the bond. c. gravitational forces between the atoms in the bond. d. equal sharing of electrons by the atoms in the bond. 14. use the iupac nomenclature rules to give the name for this compound. n₂o₃. a. nitrogen trioxide c. dinitrogen trioxide b. nitrogen(ii) oxide d. nitrogen oxide 15. use vsepr theory to predict the electron - pair geometry of bh₃. a. tetrahedral c. trigonal planar b. trigonal bipyramidal d. linear 16. which gas has the shortest bond length between its two atoms? a. hi c. cl₂ b. o₂ d. n₂

Explanation:

10.

Step1: Determine the formula

Selenium hexafluoride is \(SeF_6\). In \(SeF_6\), Se has 6 bonding pairs (since it bonds with 6 F atoms).

Step1: Analyze \(BeH_2\)

For \(BeH_2\), the central atom Be has 2 bonding pairs and 0 lone pairs. According to VSEPR, its molecular geometry is linear.

Step2: Analyze \(H_2S\), \(H_2O\), \(SeH_2\)

For \(H_2S\), \(H_2O\), \(SeH_2\), the central atoms (S, O, Se) have 2 bonding pairs and 2 lone pairs. According to VSEPR, their molecular geometries are bent.

Step1: Recall properties of \(CCl_4\)

\(CCl_4\) is a non - polar molecule. Hydrogen bonds occur between molecules with \(N - H\), \(O - H\) or \(F - H\) bonds. Metallic bonds are in metals. Dipole - dipole forces are between polar molecules. London/dispersion forces are between non - polar molecules.

Answer:

C. 6

11.