Look at the location of elements A, B, C, and D in the following periodic table:

(e) Which of these oxides has the highest melting point? Which has the lowest melting point?

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

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

(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:

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

(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.

Which of the following elements (X) will form a covalent hydride with the formula XH₃ that is a gas at room temperature? (LO 22.4)

(a) Al (b) As (c) Ba (d) Se

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

Which element in each of the following pairs has more nonmetallic character?

(a) Se or Te

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

(b) P4O6 or Ga2O3

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

Consider the elements C, Se, B, Sn, and Cl. Identify which of these elements:

c. Is the best electrical conductor

Consider the elements C, Se, B, Sn, and Cl. Identify which of these elements:

e. Forms a hydride with the empirical formula 

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

c. Is a semiconductor

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

Complete and balance the equation for each of the following reactions.

b. Ca(s) + H₂O(l) →

Complete and balance the equation for each of the following reactions.

d. $C_2H_6\left(g\right)+H_2O\left(g\right)\overset{heat}{\underset{catalyst}\rightarrow}$

Compare some of the physical properties of H₂S, NaH, and PdH_x.

Identify the group 3A element that best fits each of the following descriptions.

(c) Is extremely toxic

List three ways in which the properties of boron differ from those of the other group 3A elements.

Explain why the properties of boron differ so markedly from the properties of the other group 3A elements.

Describe the structure of diborane (B₂H₆) and explain why the bridging B–H bonds are longer than the terminal B–H bonds.

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

b. Is the least dense semimetal

Which of the following oxides will be more soluble in acidic solution? (LO 22.14)

(a) SiO2 (b) NO2

(c) BaO (d) B2O3

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

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?

The following pictures represent structures of the hydrides of four second-row elements:

(1)

(2)

(3)

(4)

(c) Which compounds yield H2 gas when they are mixed together?

In the following pictures of oxides, red spheres represent O atoms or ions, and green spheres represent atoms or ions of a second- or third-row element in its highest oxidation state.

(1)

(2)

(3)

(b) Identify each oxide as ionic or covalent.