Nitrogen has relatively stable isotopes (half-life greater than 1 second) of mass ­numbers 13, 14, 15, 16, and 17. All except ¹⁴N and ¹⁵N are radioactive.) Calculate how many protons and neutrons are in each of these isotopes of nitrogen.

Write the electronic configurations of the third-row elements shown in the partial ­periodic table in Figure 1-6.

Use your molecular models to make ethane, and compare the model with the preceding structures.

Draw Lewis structures for the following compounds.

e. dimethylamine, CH₃NHCH₃

f. diethyl ether, CH₃CH₂OCH₂CH₃

g. 1-chloropropane,CH₃CH₂CH₂Cl

Write Lewis structures for the following molecular formulas. Circle any lone pairs (pairs of nonbonding electrons) in the structures.

i. C₃H₆ (one double bond)

j. C₃H₄ (two double bonds)

k. C₃H₄ (one triple bond)

Use electronegativities to predict the direction of the dipole moments of the following bonds.

(f) N—Cl

(g) N—O

(h) N—S

(i) N—B

(j) B—Cl

Draw Lewis structures for the following compounds and ions, showing appropriate ­formal charges.

(e) ⁺CH₃

(f) ^–CH₃

(g) NaBH₄

(h) NaBH₃CN

Draw Lewis structures for the following compounds and ions, showing appropriate ­formal charges.

(i) (CH₃)₂O—BF₃

(j) [HONH₃]⁺

(k) KOC(CH₃)₃

(l) [H₂C=OH]⁺

Draw the important resonance forms for the following molecules and ions.

(a) CO₃^2–

(b)

(c)

Draw the important resonance forms for the following molecules and ions.

(d) NO₃^–

(e) NO₂^–

(f)

For each of the following compounds, draw the important resonance forms. Indicate which structures are major and minor contributors or whether they have the same energy.

(c) [H₂COCH₃]⁺

For each of the following compounds, draw the important resonance forms. Indicate which structures are major and minor contributors or whether they have the same energy.

(d) [H₂CNO₂]^–

For each of the following compounds, draw the important resonance forms. Indicate which structures are major and minor contributors or whether they have the same energy.

(e) [CH₃C(OH)₂]⁺

(f) [CH₂CHNH]^–

For each of the following compounds, draw the important resonance forms. Indicate which structures are major and minor contributors or whether they have the same energy.

(g)

(h)

Draw the important resonance forms of the following cations and anions:

(c)

(d)

Use resonance structures to identify the areas of high and low electron density in the following compounds:

(c)

Use resonance structures to identify the areas of high and low electron density in the following compounds:

(d)

Draw complete Lewis structures for the following condensed structural formulas.

(d) CH₂CHCHO

(e) (CH₃)₃CCOCHCH₂

Give Lewis structures corresponding to the following line–angle structures. Give the molecular formula for each structure.

(a)

(b)

Give Lewis structures corresponding to the following line–angle structures. Give the molecular formula for each structure.

(c)

(d)

Give Lewis structures corresponding to the following line–angle structures. Give the molecular formula for each structure.

(e)

(f)

Give Lewis structures corresponding to the following line–angle structures. Give the molecular formula for each structure.

(g)

(h)

Draw line-angle structures for the compounds (a) through (h).

a. CH₃(CH₂)₃CH(CH₃)₂ 

b. (CH₃)₂CHCH₂Cl 

Draw line-angle structures for the compounds (a) through (h).

c. CH₃CH₂COCN

d. CH₂CHCHO

Draw line-angle structures for the compounds (a) through (h).

e. (CH₃)₃CCOCHCH₂

f. CH₃COCOOH

Draw line-angle structures for the compounds (a) through (h).

g. (CH₃CH₂)₂CO

h. (CH₃)₃COH

Compute the empirical and molecular formulas for each of the following elemental analyses. In each case, propose at least one structure that fits the molecular formula.

Compute the empirical and molecular formulas for each of the following elemental analyses. In each case, propose at least one structure that fits the molecular formula.

Compute the empirical and molecular formulas for each of the following elemental analyses. In each case, propose at least one structure that fits the molecular formula.