Refer to Figure 10.2 to find the electronegativity

Examine the formulas and space-filling models of the molecules shown here. Determine whether the structure is correct. If the structure is incorrect, sketch the correct structure.

Why are bonding theories important? Cite some examples of what bonding theories can predict.

PROBLEM 3Q In the Lewis model, what is an octet? What is a duet? What is a chemical bond?

PROBLEM 2Q Write the electron configurations for Ne and Ar. How many valence electrons does each element have?

How can the Lewis model be used to determine the formula of ionic compounds? You may explain this with an example.

PROBLEM 4Q What is the difference between ionic bonding and covalent bonding?

What is the difference between lone pair and bonding pair electrons?

How are double and triple bonds physically different from single bonds?

What is the procedure for writing a covalent Lewis structure?

How do you determine the number of electrons that go into the Lewis structure of a molecule?

How do you determine the number of electrons that go into the Lewis structure of a polyatomic ion?

Why does the octet rule have exceptions? List some examples.

What are resonance structures? Why are they necessary?

Explain how VSEPR theory predicts the shapes of molecules.

If all of the electron groups around a central atom are bonding groups (that is, there are no lone pairs), what is the molecular geometry for: (a) two electron groups (b) three electron groups (c) four electron groups

Give the bond angles for each of the geometries in the preceding question.

What is the difference between electron geometry and molecular geometry in VSEPR theory?

What is electronegativity?

What is the most electronegative element on the periodic table?

What is a polar covalent bond?

PROBLEM 20Q What is a dipole moment?

What happens if you try to mix a polar liquid with a nonpolar one?

PROBLEM 22Q If a molecule has polar bonds, is the molecule itself polar? Why or why not?

Write an electron configuration for each element and the corresponding Lewis structure. Indicate which electrons in the electron configuration are included in the Lewis structure. (a) N (b) C (c) Cl (d) Ar

Write an electron configuration for each element and the corresponding Lewis structure. Indicate which electrons in the electron configuration are included in the Lewis structure. (a) Li (b) P (c) F (d) Ne

Write the Lewis structure for each element. (a) I (b) S (c) Ge (d) Ca

Write the Lewis structure for each element. (a) Kr (b) P (c) B (d) Na

Write a generic Lewis structure for the halogens. Do the halogens tend to gain or lose electrons in chemical reactions? How many?

Write a generic Lewis structure for the alkali metals. Do the alkali metals tend to gain or lose electrons in chemical reactions? How many?

Write a generic Lewis structure for the alkaline earth metals. Do the alkaline earth metals tend to gain or lose electrons in chemical reactions? How many?

Write a generic Lewis structure for the elements in the oxygen family (Group 6A). Do the elements in the oxygen family tend to gain or lose electrons in chemical reactions? How many?

Write the Lewis structure for each ion. (a) \(A l^{3+}\) (b) \(M g^{2+}\) (c) \(S e^{2-}\) (d) \(N^{3-}\) Equation Transcription: Text Transcription: Al^3+ Mg^2+ Se^2- N^3-

Write the Lewis structure for each ion. (a) \(S r^{2+}\) (b) \(S^{2-}\) (c) \(L i^{+}\) (d) \(C l^{-}\) Equation Transcription: Text Transcription: Sr^2+ S^2- Li^+ Cl^-

Indicate the noble gas that has the same Lewis structure as each ion. (a) \(B r^{-}\) (b) \(O^{2-}\) (c) \(R b^{+}\) (d) \(B a^{2+}\) Equation Transcription: Text Transcription: Br^- O^2- Rb^+ Ba^2+

Indicate the noble gas that has the same Lewis structure as each ion. (a) \(S e^{2-}\) (b) \(I^{-}\) (c) \(S r^{2+}\) (d) \(F^{-}\) Equation Transcription: Text Transcription: Se^2- I^- Sr^2+ F^-

Is each compound best represented by an ionic or a covalent Lewis structure? (a) \(S F_{6}\) (b) \(\mathrm{MgCl}_{2}\) (c) \(\mathrm{BrCl}\) (d) \(K_{2} S\) Equation Transcription: Text Transcription: SF_6 MgCl_2 BrCl K_2 S

Is each compound best represented by an ionic or a covalent Lewis structure? (a) \(N O\) (b) \(\mathrm{CO}_{2}\) (c) \(\mathrm{Rb}_{2} \mathrm{O}\) (d) \(A l_{2} S_{3}\) Equation Transcription: Text Transcription: NO CO_2 Rb_2 O Al_2 S_3

Write the Lewis structure for each ionic compound. (a) \(N a F\) (b) \(\mathrm{CaO}\) (c) \(S r B r_{2}\) (d) \(\mathrm{K}_{2} \mathrm{O}\) Equation Transcription: Text Transcription: NaF CaO SrBr_2 K_2 O

Write the Lewis structure for each ionic compound. (a) \(S r O\) (b) \(L i_{2} S\) (c) \(\mathrm{CaI}_{2}\) (d) \(R b F\) Equation Transcription: Text Transcription: SrO Li_2 S CaI_2 RbF

PROBLEM 39P Use the Lewis model to determine the formula for the compound that forms from each pair of atoms. (a) Ca and S (b) Mg and Br (c) Cs and I (d) Ca and N

PROBLEM 40P Use the Lewis model to determine the formula for the compound that forms from each pair of atoms. (a) Al and S (b) Na and S (c) Sr and Se (d) Ba and F

Draw the Lewis structure for the ionic compound that forms from Mg and each atom. (a) F (b) O (c) N

Draw the Lewis structure for the ionic compound that forms from Al and each atom. (a) F (b) O (c) N

Determine what is wrong with each ionic Lewis structure and write the correct structure. (a) \([C s:]^{+}[: C l:]^{-}\) (b) \(B a^{+}[: \ddot{O}:]^{-}\) (c) \(C a^{2+}[: \ddot{I}:]^{-}\)

Determine what is wrong with each ionic Lewis structure and write the correct structure. (a) \([: \ddot{\mathrm{O}}:]^{2-} \mathrm{Na}^{+}[: \ddot{\mathrm{G}}:]^{2-}\) (b) \(Mg: \ddot{\mathrm{O}}:\) (c) \([Li:]^+[: \ddot{\mathrm{S}}:]^-\) Equation Transcription: Text Transcription: [:O:]^2- Na^+ [:O:]^2- Mg :O: [Li:]^+ [:S:]^-

Use the Lewis model to explain why each element exists as a diatomic molecule. (a) hydrogen (b) iodine (c) nitrogen (d) oxygen

Use the Lewis model to explain why the compound that forms between hydrogen and sulfur has the formula \(H_{2} S\). Would you expect HS to be stable? H_{3} S? Equation Transcription: Text Transcription: H_2 S H_3 S

Write the Lewis structure for each molecule. (a) \(\mathrm{PH}_{3}\) (b) \(\mathrm{SCl}_{2}\) (c) \(F_{2}\) (d) \(H I\) Equation Transcription: Text Transcription: PH_3 SCl_2 F_2 HI

Write the Lewis structure for each molecule. (a) \(\mathrm{CH}_{4}\) (b) \(N F_{3}\) (c) \(O F_{2}\) (d) \(\mathrm{H}_{2} \mathrm{O}\) Equation Transcription: Text Transcription: CH_4 NF_3 OF_2 H_2 O

Write the Lewis structure for each molecule. (a) \(O^{2}\) (b) \(C O\) (c) \(\text { HONO }\) (N is central; H bonded to one of the O atoms.) (d) \(\mathrm{SO}_{2}\) Equation Transcription: Text Transcription: O^2 CO HONO SO_2

Write the Lewis structure for each molecule. (a) \(\mathrm{N}_{2} \mathrm{O}\) (oxygen is terminal) (b) \(\mathrm{SiH}_{4}\) (c) \(\mathrm{CI}_{4}\) (d) \(\mathrm{Cl}_{2} \mathrm{CO}\) (carbon is central) Equation Transcription: Text Transcription: N_2 O SiH_4 CI_4 Cl_2 CO

Write the Lewis structure for each molecule. (a) \(C_{2} H_{2}\) (b) \(C_{2} H_{4}\) (c) \(\mathrm{N}_{2} \mathrm{H}_{2}\) (d) \(\mathrm{N}_{2} \mathrm{H}_{4}\) Equation Transcription: Text Transcription: C_2 H_2 C_2 H_4 N_2 H_2 N_2 H_4

Write the Lewis structure for each molecule. (a) \(\mathrm{H}_{2} \mathrm{CO}\) (carbon is central) (b) \(\mathrm{H}_{3} \mathrm{COH}\) (carbon and oxygen are both central) (c) \(\mathrm{H}_{3} \mathrm{COCH}_{3}\) (oxygen is between the two carbon atoms) (d) \(\mathrm{H}_{2} \mathrm{O}_{2}\) Equation Transcription: Text Transcription: H_2 CO H_3 COH H_3 COCH_3 H_2 O_2

Determine what is wrong with each Lewis structure and write the correct structure.

Determine what is wrong with each Lewis structure and write the correct structure.

Write the Lewis structure for each molecule or ion. Include resonance structures if necessary. (a) \(\mathrm{SeO}_{2}\) (b) \(\mathrm{CO}_{3}{ }^{2-}\) (c) \(\mathrm{ClO}^{-}\) (d) \(\mathrm{ClO}_{2}^{-}\) Equation Transcription: Text Transcription: SeO_2 CO_3 ^2- ClO^- ClO_2 ^-

Write the Lewis structure for each molecule or ion. Include resonance structures if necessary. (a) \(\mathrm{CIO}_{3}^{-}\) (b) \(\mathrm{CIO}_{4}{ }^{-}\) (c) \(\mathrm{NO}_{3}{ }^{-}\) (d) \(\mathrm{SO}_{3}\) Equation Transcription: Text Transcription: CIO_3 ^- CIO_4 ^- NO_3 SO_3

Write the Lewis structure for each ion. Include resonance structures if necessary. (a) \(\mathrm{PO}_{4}{ }^{3-}\) (b) \(C N^{-}\) (c) \(\mathrm{NO}_{2}{ }^{-}\) (d) \(\mathrm{SO}_{3}{ }^{2-}\) Equation Transcription: Text Transcription: PO_4 ^3- CN^- NO_2 ^- SO_3 ^2-

Write the Lewis structure for each ion. Include resonance structures if necessary. (a) \(\mathrm{SO}_4^{2-}\) (b) \(\mathrm{HSO}_4{ }^{-}\) (S is central; H is attached to one of the O atoms) (c) \(\mathrm{NH}_4+\) (d) \(\mathrm{BrO}_2^{-}\) (Br is central)

Write the Lewis structure for each ion. Include resonance structures if necessary. (a) \(\mathrm{BCl}_{3}\) (b) \(\mathrm{NO}_{2}\) (c) \(\mathrm{BH}_{3}\) Equation Transcription: Text Transcription: BCl_3 NO_2 BH_3

Write the Lewis structure for each molecule. These molecules do not follow the octet rule. (a) \(B B r_{3}\) (b) \(N O\) Equation Transcription: Text Transcription: BBr_3 NO

Determine the number of electron groups around the central atom for each molecule. (a) \(O F_{2}\) (b) \(N F_{3}\) (c) \(C S_{2}\) (d) \(C H_{4}\) Equation Transcription: Text Transcription: OF_2 NF_3 CS_2 CH_4

Determine the number of electron groups around the central atom for each molecule. (a) \(\mathrm{CH}_{2} \mathrm{Cl}_{2}\) (b) \(S B r_{2}\) (c) \(\mathrm{H}_{2} \mathrm{~S}\) (d) \(\mathrm{PCl}_{3}\) Equation Transcription: Text Transcription: CH_2 Cl_2 SBr_2 H_2 S PCl_3

Determine the number of bonding groups and the number of lone pairs for each of the molecules in Problem 61. The sum of these should equal your answers to Problem 61.

Determine the number of bonding groups and the number of lone pairs for each of the molecules in Problem 62. The sum of these should equal your answers to Problem 62.

Determine the molecular geometry of each molecule. (a) \(C B r_{4}\) (b) \(\mathrm{H}_{2} \mathrm{CO}\) (c) \(C S_{2}\) (d) \(\mathrm{BH}_{3}\) Equation Transcription: Text Transcription: CBr_4 H_2 CO CS_2 BH_3

Determine the molecular geometry of each molecule. (a) \(\mathrm{SiO}_{2}\) (b) \(B F_{3}\) (c) \(\mathrm{CFCl}_{3}\) (carbon is central) (d) \(\mathrm{H}_{2} \mathrm{CS}\) (carbon is central) Equation Transcription: Text Transcription: SiO_2 BF_3 CFCl_3 H_2 CS

Determine the bond angles for each molecule in Problem 66.

Determine the electron and molecular geometries of each molecule. (a) \(\mathrm{N}_{2} \mathrm{O}\) (oxygen is terminal) (b) \(\mathrm{SO}_{2}\) (c) \(H_{2} S\) (d) \(P F_{3}\) Equation Transcription: Text Transcription: N_2 O SO_2 H_2 S PF_3

Determine the bond angles for each molecule in Problem 65.

Determine the electron and molecular geometries of each molecule. (Hint: Determine the geometry around each of the two central atoms.) (a) \(\mathrm{C}_{2} \mathrm{H}_{2}\) (skeletal structure HCCH) (b) \(C_{2} H_{4}\) (skeletal structure \(\mathrm{H}_{2} \mathrm{CCH}_{2}\)) (c) \(C_{2} H_{6}\) (skeletal structure \(\mathrm{H}_{3} \mathrm{CCH}_{3}\)) Equation Transcription: Text Transcription: C_2 H_2 C_2 H_4 C_2 H_6 H_2 CCH_2 H_3 CCH_3

Determine the bond angles for each molecule in Problem 69.

PROBLEM 73P Determine the electron and molecular geometries of each molecule. For molecules with two central atoms, indicate the geometry about each central atom. (a) N2 (b) N2H2 (skeletal structure HNNH) (c) N2H4 (skeletal structure H2NNH2)

PROBLEM 74P Determine the electron and molecular geometries of each molecule. For molecules with more than one central atom, indicate the geometry about each central atom. (a) CH3OH (skeletal structure H3COH) (b) H3COCH3 (skeletal structure H3COCH3) (c) H2O2 (skeletal structure HOOH)

PROBLEM 75P Determine the molecular geometry of each polyatomic ion. (a) CO32? (b) ClO2? (c) NO3? (d) NH4+

PROBLEM 76P Determine the molecular geometry of each polyatomic ion. (a) ClO4? (b) BrO2? (c) NO2? (d) SO42?

PROBLEM 72P Determine the bond angles for each molecule in. (a) C2H2 (skeletal structure HCCH) (b) C2H4 (skeletal structure H2CCH2) (c) C2H6 (skeletal structure H3CCH3)

Refer to Figure \(10.2\) to determine the electronegativity of each element. (a) \(Mg\) (b) \(Si\) (c) \(Br\) Equation Transcription: Text Transcription: 10.2 Mg Si Br

Refer to Figure \(10.2\) to determine the electronegativity of each element. (a) \(F\) (b) \(C\) (c) \(S\) Equation Transcription: Text Transcription:

List these elements in order of decreasing electronegativity: Rb, Si, Cl, Ca, Ga.

Refer to Figure \(10.2\) to find the electronegativity difference between each pair of elements; then refer to Table \(10.2\) to classify the bonds that occur between them as pure covalent, polar covalent, or ionic. (a) Mg and Br (b) Cr and F (c) Br and Br (d) Si and O Equation Transcription: Text Transcription: 10.2

List these elements in order of increasing electronegativity: Ba, N, F, Si, Cs.

Arrange these diatomic molecules in order of increasing bond polarity: ICl, HBr, \(H_{2}\), CO. Equation Transcription: Text Transcription: H_2

Arrange these diatomic molecules in order of decreasing bond polarity: HCl, NO, \(F_{2}\), HI Equation Transcription: Text Transcription: F_2

Refer to Figure \(10.2\) to find the electronegativity difference between each pair of elements; then refer to Table \(10.2\) to classify the bonds that occur between them as pure covalent, polar covalent, or ionic. (a) K and Cl (b) N and N (c) C and S (d) C and Cl Equation Transcription: Text Transcription: 10.2

Classify each diatomic molecule as polar or nonpolar. (a) \(I^{2}\) (b) \(N O\) (c) \(H C I\) (d) \(N_{2}\) Equation Transcription: Text Transcription: I^2 NO HCI N_2

Classify each diatomic molecule as polar or nonpolar. (a) \(\mathrm{CO}\) (b) \(\mathrm{O}_{2}\) (c) \(F_{2}\) (d) \(H B r\) Equation Transcription: Text Transcription: CO O_2 F_2 HBr

For each polar molecule in Problem 85 draw the molecule and indicate the positive and negative ends of the dipole moment.

For each polar molecule in Problem 86 draw the molecule and indicate the positive and negative ends of the dipole moment.

Classify each molecule as polar or nonpolar. (a) \(C S_{2}\) (b) \(\mathrm{SO}_{2}\) (c) \(\mathrm{CH}_{4}\) (d) \(\mathrm{CH}_{3} \mathrm{Cl}\) Equation Transcription: Text Transcription: CS_2 SO_2 CH_4 CH_3 Cl

Classify each molecule as polar or nonpolar. (a) \(\mathrm{BH}_{3}\) (b) \(\mathrm{CHCl}_{3}\) (c) \(C_{2} H_{2}\) (d) \(\mathrm{NH}_{3}\) Equation Transcription: Text Transcription: BH_3 CHCl_3 C_2 H_2 NH_3

Classify each molecule as polar or nonpolar. (a) \(\mathrm{N}_{2} \mathrm{H}_{2}\) (b) \(\mathrm{H}_{2} \mathrm{O}_{2}\) (c) \(\mathrm{CF}_{4}\) (d) \(\mathrm{NO}_{2}\)

Classify each molecule as polar or nonpolar. (a) \(\mathrm{H}_{2} \mathrm{CO}\) (b) \(\mathrm{CH}_{3} \mathrm{OH}\) (c) \(\mathrm{CH}_{2} \mathrm{Cl}_{2}\) (d) \(\mathrm{CO}_{2}\) Equation Transcription: Text Transcription: H_2 CO CH_3 OH CH_2 Cl_2 CO_2

Write electron configurations and Lewis structures for each element. Indicate which of the electrons in the electron configuration are shown in the Lewis structure. (a) Rb (b) Ge (c) Kr (d) Se

Write electron configurations and Lewis structures for each element. Indicate which of the electrons in the electron configuration are shown in the Lewis structure. (a) Ca (b) Ga (c) As (d) I

Determine whether each compound is ionic or covalent and write the appropriate Lewis structure. (a) \(K_{2} S\) (b) \(\text { CHFO }\) (carbon is central) (c) \(\text { MgSe }\) (d) \(P B r_{3}\) Equation Transcription: Text Transcription: K_2 S CHFO MgSe PBr_3

Write the Lewis structure for \(\mathrm{OCCl}_{2}\) (carbon is central) and determine whether the molecule is polar. Draw the three-dimensional structure of the molecule. Equation Transcription: Text Transcription: OCCl_2

Write the Lewis structure for \(\mathrm{CH}_{3} \mathrm{COH}\) and determine whether the molecule is polar. Draw the three-dimensional structure of the molecule. The skeletal structure is: Equation Transcription: CH3COH Text Transcription: CH_3COH

Write the Lewis structure for acetic acid (a component of vinegar) \(\mathrm{CH}_{3} \mathrm{COOH}\), and draw the three-dimensional sketch of the molecule. Its skeletal structure is: Equation Transcription: CH3COOH Text Transcription: CH_3COOH

Consider the neutralization reaction. \(\mathrm{HCl}(a q)+\mathrm{NaOH}(a q) \rightarrow \mathrm{H}_{2} \mathrm{O}(l)+\mathrm{NaCl}(a q)\) Write the reaction showing the Lewis structures of each of the reactants and products. Equation Transcription: Text Transcription: HCI(aq) + NaOH(aq) right arrow H_2 O(l) + NaCl(aq)

Write the Lewis structure for benzene, \(\mathrm{C}_{6} \mathrm{H}_{8}\), and draw a three-dimensional sketch of the molecule. The skeletal structure is the ring shown here. (Hint: The Lewis structure consists of two resonance structures.) Equation Transcription: C6H6 Text Transcription: C_6H_6

Determine whether each compound is ionic or covalent and write the appropriate Lewis structure. (a) \(H C N\) (b) \(\text { CIF }\) (c) \(\mathrm{MgI}_{2}\) (d) \(\text { CaS }\) Equation Transcription: Text Transcription: HCN CIF MgI_2 CaS

Consider the precipitation reaction. \(\mathrm{Pb}\left(\mathrm{NO}_{3}\right)_{2}(a q)+2 \mathrm{LiCl}(a q) \rightarrow \mathrm{PbCl}_{2}(s)+2 \mathrm{LiNO}_{3}(a q)\) Write the reaction showing the Lewis structures of each of the reactants and products.

Each of the compounds listed contains both ionic and covalent bonds. Write an ionic Lewis structure for each one, including the covalent structure for the polyatomic ion. Write resonance structures if necessary. (a) \(\mathrm{RbIO}_{2}\) (b) \(\mathrm{Ca}(\mathrm{OH})_{2}\) (c) \(\mathrm{NH}_{4} \mathrm{Cl}\) (d) \(S r(C N)_{2}\) Equation Transcription: Text Transcription: RbIO_2 Ca(OH)_2 NH_4 Cl Sr(CN)_2

Each molecule listed contains an expanded octet (10 or 12 electrons) around the central atom. Write the Lewis structure for each molecule. (a) \(\mathrm{CIF}_{5}\) (b) \(S F_{6}\) (c) \(I F_{5}\) Equation Transcription: Text Transcription: CIF_5 SF_6 IF_5

Formic acid is responsible for the sting you feel when stung by fire ants. By mass, formic acid is 26.10% C, 4.38% H, and 69.52% O. The molar mass of formic acid is 46.02 g/mol. Find the molecular formula of formic acid and draw its Lewis structure.

Consider the redox reaction. \(\mathrm{Ca}(\mathrm{s})+\mathrm{Br}_{2}(g) \rightarrow \mathrm{CaBr}_{2}(s)\) Draw the Lewis structure for each reactant and product and determine which reactant was oxidized and which one was reduced. Equation Transcription: Text Transcription: Ca(s)+Br_2 (g) right arrow CaBr_2 (s)

Diazomethane has the following composition by mass: 28.57% C, 4.80% H, and 66.64% N. The molar mass of diazomethane is 42.04 g/mol . Find the molecular formula of diazomethane and draw its Lewis structure.

Free radicals are molecules that contain an odd number of valence electrons and therefore contain an unpaired electron in their Lewis structure. Write the best possible Lewis structure for the free radical HOO. Does the Lewis model predict that HOO is stable? Predict its geometry.

Each compound listed contains both ionic and covalent bonds. Write the ionic Lewis structure for each one including the covalent structure for the polyatomic ion. Write resonance structures if necessary. (a) \(\mathrm{KOH}\) (b) \(\mathrm{KNO}_{3}\) (c) \(\text { LiIO }\) (d) \(\mathrm{BaCO}_{3}\) Equation Transcription: Text Transcription: KOH KNO_3 LiIO BaCO_3

Free radicals (as explained in the previous problem) are molecules that contain an odd number of valence electrons. Write the best possible Lewis structure for the free radical \(\mathrm{CH_3}\). Predict its geometry.

Each molecule listed contains an expanded octet (10 or 12 electrons) around the central atom. Write the Lewis structure for each molecule. (a) \(\mathrm{PF}_5\) (b) \(\mathrm{SF}_4\) (c) \(\mathrm{SeF}_4\)

Consider the redox reaction. \(2 \mathrm{~K}(\mathrm{~s})+\mathrm{Cl}_{2}(g) \rightarrow 2 \mathrm{KCl}(s)\) Draw the Lewis structure for each reactant and product and determine which reactant was oxidized and which one was reduced. Equation Transcription: Text Transcription: 2K(s)+Cl_2 (g) right arrow 2KCl(s)

Free radicals (see Problem \(113\)) are important in many environmentally significant reactions. For example, photochemical smog, which forms as a result of the action of sunlight on air pollutants, is formed in part by these two steps: \(\mathrm{NO}_{2} \stackrel{\text { UV light }}{\rightarrow} \mathrm{NO}+\mathrm{O}\) \(O+O_{2} \rightarrow O_{3}\) The product of this reaction, ozone, is a pollutant in the lower atmosphere. Ozone is an eye and lung irritant and also accelerates the weathering of rubber products. Write Lewis structures for each of the reactants and products in the preceding reactions. Equation Transcription: Text Transcription: 113 NO_2 UV light^rightarrow NO + O O + O_2 rightarrow O_3

Some theories on aging suggest that free radicals cause a variety of diseases and aging. Free radicals (as explained in Problems 111 and 112) are molecules or ions containing an unpaired electron. As you know from the Lewis model, such molecules are not chemically stable and quickly react with other molecules. Free radicals may attack molecules within the cell, such as DNA, changing them and causing cancer or other diseases. Free radicals may also attack molecules on the surfaces of cells, making them appear foreign to the body’s immune system. The immune system then attacks the cell and destroys it, weakening the body. Draw the Lewis structure for each of these free radicals, which have been implicated in theories of aging. (a) \(\mathrm{O}_{2}{ }^{-}\) (b) \(O^{-}\) (c) \(O H\) (d) \(\mathrm{CH}_{3} \mathrm{OO}\) (unpaired electron on terminal oxygen)