Question

which of the following lewis symbols is correct? li· ·ge· ·n· ·sb· a b c d a.a c.c b.b d.d question 19 which represents a compound with only ionic bonds? c.nh4cl a.ca(oh)2 b.nf3 d.mgf2 question 20 which of the following has 11 valence electrons? c.no a.sh b.io d.cl

Explanation:

Step1: Recall valence - electron rules for Lewis symbols

Lewis symbols represent the valence electrons of an atom as dots around the chemical symbol. Lithium (Li) has 1 valence electron, Germanium (Ge) has 4 valence electrons, Nitrogen (N) has 5 valence electrons, and Antimony (Sb) has 5 valence electrons. The correct Lewis symbol for N should have 5 dots around it. The given 'N' symbol has 3 dots which is incorrect. The correct Lewis symbol for Li is Li• (1 dot), for Ge is •Ge• with 4 dots around it, for Sb is similar to N with 5 dots around it. So, the correct Lewis - symbol among them is Li•.

Step2: Analyze ionic - bond compounds

Ionic bonds form between a metal and a non - metal. In Ca(OH)₂, there are both ionic (between Ca²⁺ and OH⁻) and covalent (within OH⁻) bonds. In NH₄Cl, there are ionic (between NH₄⁺ and Cl⁻) and covalent (within NH₄⁺) bonds. NF₃ is a covalent compound as it is formed between non - metals. MgF₂ is a compound with only ionic bonds as it is formed between the metal Mg²⁺ and non - metal F⁻.

Step3: Calculate valence electrons

For SH, S has 6 valence electrons and H has 1 valence electron, so total = 6 + 1=7. For IO, I has 7 valence electrons and O has 6 valence electrons, so total = 7+6 = 13. For NO, N has 5 valence electrons and O has 6 valence electrons, so total = 5 + 6=11. For ICl, I has 7 valence electrons and Cl has 7 valence electrons, so total = 7+7 = 14.

Answer:

a. a.a
d. d.MgF2
c. c.NO