For each of these Lewis symbols, indicate the group in the periodic table in which the element X belongs: (a)

Illustrated are four ions — A, B, X, and Y— showing their relative ionic radii. The ions shown in red carry positive charges: a 2+ charge for A and a 1+ charge for B. Ions shown in blue carry negative charges: a 1- charge for X and a 2- charge for Y. (b) Among the combinations in part (a), which leads to the ionic compound having the largest lattice energy?

A portion of a two-dimensional 'slab' of NaCl(s) is shown here (see Figure 8.2) in which the ions are numbered. (a) Which colored balls must represent sodium ions?

A portion of a two-dimensional 'slab' of NaCl(s) is shown here (see Figure 8.2) in which the ions are numbered. (d) Consider ion 5. How many repulsive interactions are shown for it?

The orbital diagram that follows shows the valence electrons for a 3+ ion of an element. (a) What is the element?

Which of the following charts shows the general periodic trends for the electronegativities of the representative elements? [Section 8.4]

A molecule with formula C4H3NO has the connectivity shown in the figure. After the Lewis structure of the molecule is completed, how many of each of the following are there in the molecule:

a. single bonds,

b. double bonds,

c. triple bonds,

d. nonbonding pairs? [Sections 8.3 and 8.5]

In the Lewis structure shown here, A, D, E, Q, X, and Z represent elements in the first two rows of the periodic table. Identify all six elements so that the formal charges of all atoms are zero.

The molecule shown here is styrene, C8H8, a benzene derivative that is used to make a number of polymers, including polystyrene. The shorthand notation for the benzene ring (described in Section 8.6) is used. Three of the carbon–carbon bonds are numbered in the structure.

a. Which of the three bonds is the strongest?

b. Which of the three bonds is the longest?

c. Which of the three bonds is best described as halfway between a single and a double bond? [Sections 8.6 and 8.8]

Consider the Lewis structure for the polyatomic oxyanion shown here, where X is an element from the third period (Na - Ar). By changing the overall charge, n, from 1- to 2- to 3- we get three different polyatomic ions. For each of these ions (b) determine the formal charge of the central atom, X;

(a) True or false: An element's number of valence electrons is the same as its atomic number.

(b) How many valence electrons does a nitrogen atom possess?

(c) An atom has the electron configuration 1s²2s²2p⁶3s²3p². How many valence electrons does the atom have?

(a) True or false: The hydrogen atom is most stable when it has a full octet of electrons.

Consider the element silicon, Si. (c) Which subshells hold the valence electrons?

(a) Write the electron configuration for the element titanium, Ti. How many valence electrons does this atom possess?

(b) Hafnium, Hf, is also found in group 4. Write the electron configuration for Hf.

(c) Ti and Hf behave as though they possess the same number of valence electrons. Which of the subshells in the electron configuration of Hf behave as valence orbitals? Which behave as core orbitals?

Write the Lewis symbol for atoms of each of the following elements: (c) Ar

What is the Lewis symbol for each of the following atoms or ions: c. Sn²⁺

(a) Using Lewis symbols, make a sketch of the reaction between magnesium and oxygen atoms to give the ionic substance MgO

Predict the chemical formula of the ionic compound formed between the following pairs of elements: (b) K and S

Predict the chemical formula of the ionic compound formed between the following pairs of elements: (d) Mg and N

Which ionic compound is expected to form from combining the following pairs of elements? c. lithium and nitrogen

Which ionic compound is expected to form from combining the following pairs of elements? (d) aluminum and oxygen.

Write the electron configuration for each of the following ions, and determine which ones possess noble-gas configurations: a. Rb+ b. Rh3+ c. P3− d. Sc3+ e. S2− f. V2+.

(b) Write the chemical equation that represents the process of lattice energy for the case of NaCl.

(c) Would you expect salts like NaCl, which have singly charged ions, to have larger or smaller lattice energies compared to salts like CaO which are composed of doubly-charged ions?

NaCl and KF have the same crystal structure. The only difference between the two is the distance that separates cations and anions. (a) The lattice energies of NaCl and KF are given in Table 8.1. Based on the lattice energies, would you expect the Na─Cl or the K─F distance to be longer?

NaCl and KF have the same crystal structure. The only difference between the two is the distance that separates cations and anions. (b) Use the ionic radii given in Figure 7.8 to estimate the Na─Cl and K─F distances.