23. Chemistry of the Nonmetals

What is the most common type of chemical bonding found within I₂ solid?

Suggest a plausible structure for the silicate anion in the mineral thortveitite, Sc₂Si₂O₇.

In what forms is oxygen commonly found in nature?

Draw the electron-dot structure for CO, CO₂, and CO₃^2–, and predict which substance will have the strongest carbon–oxygen bond.

Describe the molecular geometry of:

(b) AsH3

a. Why is the SO₃ molecule trigonal planar but the SO₃^2– ion is trigonal pyramidal?

Which compound in each of the following pairs is more ionic?

(b) P4O6 or Ga2O3

Locate each of the following elements on the periodic table.

(f) Group 5A element that forms the strongest p bonds

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Which compound in each of the following pairs is more ionic?

(d) BCl₃ or AlCl₃

Which compound in each of the following pairs is more covalent?

(a) PCl₃ or AlF₃

Give one example from main-group chemistry that illustrates each of the following descriptions.

d. Polar molecule that violates the octet rule

Using the shorthand notation of Figure 22.9, draw the structure of the cyclic silicate anion in which four SiO₄ tetrahedra share O atoms to form an eight-membered ring of alternating Si and O atoms. Give the formula and charge of the anion.

Describe the structures of the white and red allotropes of phosphorus, and explain why white phosphorus is so reactive.

Compare and contrast the properties of ammonia and phosphine.

GeCl₄ reacts with Cl^- to give GeCl₆^2-, but CCl₄ does not react with excess Cl^-. Explain.

What is the hybridization and geometry around carbon atoms in graphene? Explain why graphene is an excellent conductor of electricity.

Which of the group 4A elements have allotropes with the diamond structure? Which have metallic allotropes? How does the variation in the structure of the group 4A elements illustrate how metallic character varies down a periodic group?

Give an example of an ionic carbide. What is the oxidation state of carbon in this substance?

Why are CO and CN^– so toxic to humans?

Using the shorthand notation of Figure 22.9, draw the structure of the silicate anion in:

(a) K₄SiO₄ (b) Ag₁₀Si₄O₁₃

What is the relationship between the charge on the anion and the number of terminal O atoms?

Describe the molecular geometry of:

(c) SiH4

(b) Describe what is meant by a three-center, two-electron bond.

Identify the group 4A element that best fits each of the following descriptions.

(b) Forms the strongest p bonds

Consider the elements N, Si, Al, S, and F. Identify which of these elements:

c. Is a semiconductor

Identify the group 4A element that best fits each of the following descriptions.

(c) Is the second most abundant element in the Earth's crust

Select the group 4A element that best fits each of the following descriptions.

(c) Is the second most abundant element in the human body

The following pictures represent various silicate anions. Write the formula and charge of each anion.

Niobium reacts with fluorine at room temperature to give a solid binary compound that is 49.44% Nb by mass.

(c) The compound reacts with hydrogen to regenerate niobium. Write a balanced equation for the reaction.

Consider the six second- and third-row elements in groups 4A–6A of the periodic table:

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Possible structures for the binary fluorides of each of these elements in its highest oxidation state are shown below.

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(a) Identify the nonfluorine atom in each case, and write the molecular formula of each fluoride.

Consider the six second- and third-row elements in groups 4A–6A of the periodic table:

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Possible structures for the binary fluorides of each of these elements in its highest oxidation state are shown below.

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(b) Explain why the fluorides of nitrogen and phosphorus have different molecular structures but the fluorides of carbon and silicon have the same molecular structure.