Write a balanced equation for the reaction that occurs in each of the following cases: (a) Cesium is added to water.

Write a balanced equation for the reaction that occurs in each of the following cases: (c) Sodium reacts with oxygen.

(a) As described in Section 7.7, the alkali metals react with hydrogen to form hydrides and react with halogens to form halides. Compare the roles of hydrogen and halogens in these reactions. Write balanced equations for the reaction of fluorine with calcium and for the reaction of hydrogen with calcium. (b) What is the oxidation number and electron configuration of calcium in each product?

Potassium and hydrogen react to form the ionic compound potassium hydride. (b) Use data in Figures 7.10 and 7.12 to determine the energy change in kJ/mol for the following two reactions:

K(g) + H(g) → K⁺(g) + H^-(g)

K(g) + H(g) → K^-(g) + H⁺(g)

Little is known about the properties of astatine, At, because of its rarity and high radioactivity. Nevertheless, it is possible for us to make many predictions about its properties. (c) What is the chemical formula of the compound it forms with Na?

Write a balanced equation for the reaction that occurs in each of the following cases: (a) White phorphrous, P₄(s), reacts with chlorine gas. (b) Sodium metal reacts with water. (c) Sulfur reacts with hydrogen gas.

Write a balanced equation for the reaction that occurs in each of the following cases: (d) Fluorine reacts with water.

Consider the stable elements through lead (Z = 82). In how many instances are the atomic weights of the elements out of order relative to the atomic numbers of the elements?

Figure 7.4 shows the radial probability distribution functions for the 2s orbitals and 2p orbitals. (a) Which orbital, 2s or 2p, has more electron density close to the nucleus?

(b) Repeat these calculations using Slater’s rules.

(d) If you remove a single electron from a P atom, which orbital will it come from?

The As ¬ As bond length in elemental arsenic is 2.48 Å. The Cl ¬ Cl bond length in Cl2 is 1.99 Å. (a) Based on these data, what is the predicted As ¬ Cl bond length in arsenic trichlo- ride, AsCl₃, in which each of the three Cl atoms is bonded to the As atom?

The following observations are made about two hypothetical elements A and B: The A—A and B—B bond lengths in the elemental forms of A and B are 2.36 and 1.94 Å, respectively. A and B react to form the binary compound AB2, which has a linear structure (that is, ∠B-A-B=180°). Based on these statements, predict the separation between the two B nuclei in a molecule of AB2.

The As ¬ As bond length in elemental arsenic is 2.48 Å. The Cl ¬ Cl bond length in Cl2 is 1.99 Å. (b) What bond length is predicted for AsCl₃, using the atomic radii in Figure 7.7?

Elements in group 7A in the periodic table are called the halogens; elements in group 6A are called the chalcogens. (a) What is the most common oxidation state of the chalcogens compared to the halogens?

(c) Will the lithium cobalt oxide cathode expand or contract as lithium ions are inserted?

(d) Lithium is not nearly as abundant as sodium. If sodium ion batteries were developed that function in the same manner as lithium ion batteries, do you think 'sodium cobalt oxide' would still work as the electrode material? Explain.

Explain the variation in the ionization energies of carbon, as displayed in this graph:

The ionic substance strontium oxide, SrO, forms from the reaction of strontium metal with molecular oxygen. The arrangement of the ions in solid SrO is analogous to that in solid NaCl: (a) Write a balanced equation for the formation of SrO(s) from its elements.

The ionic substance strontium oxide, SrO, forms from the reaction of strontium metal with molecular oxygen. The arrangement of the ions in solid SrO is analogous to that in solid NaCl:

(b) Based on the ionic radii in Figure 7.8, predict the length of the side of the cube in the figure (the distance from the center of an atom at one corner to the center of an atom at a neighboring corner).

The ionic substance strontium oxide, SrO, forms from the reaction of strontium metal with molecular oxygen. The arrangement of the ions in solid SrO is analogous to that in solid NaCl:

(c) The density of SrO is 5.10 g>cm3. Given your answer to part (b), how many formula units of SrO are contained in the cube shown here?

In the chemical process called electron transfer, an electron is transferred from one atom or molecule to another. (We will talk about electron transfer extensively in Chapter 20.) A simple electron transfer reaction is A(g) + A(g) → A⁺(g) + A^-(g) For a representative nonmetal such as chlorine, is this process exothermic?

(a) Use orbital diagrams to illustrate what happens when an oxygen atom gains two electrons

Identify two ions that have the following ground-state electron configurations: (b) [Ar]3d⁵