Q&A Hero

Q: Electronegativity is a measure of A.the ability of a substance to conduct electricity. B.the charge on a polyatomic cation. C.the charge on a polyatomic anion. D.the ability of an atom in a molecule to attract electrons to itself. E.the oxidation number of an atom in a molecule or polyatomic anion.

Q: Which of the following compounds has polar covalent bonds: CCl4, Cl2, HCl, and KCl? A.CCl4 only B.Cl2 only C.HCl and KCl D.Cl2 and KCl E.CCl4 and HCl

Q: Place the following molecules in order from smallest to largest H-N-H bond angles: NH4+, NH3, and NH2-.A.NH4+ < NH3 < NH2-B.NH4+ < NH2- < NH3C.NH2- < NH3 < NH4+D.NH2- < NH4+ < NH3E.NH3 < NH2- < NH4+

Q: What are the approximate F-Br-F bond angles in BrF5? A.90 and 180 B.109.5 C.90 and 120 D.120 E.180

Q: What are the approximate O-S-O bond angles in SO32-?A.90B.109.5C.120D.180E.90 and 180

Q: What is the O-C-N bond angle in OCN-?A.90B.107C.109.5D.120E.180

Q: What are the approximate H-N-H bond angles in NH4+?A.109.5B.120C.109.5 and 120D.90E.90 and 120

Q: Based on electron geometries, which of the following molecules has the smallest bond angle between any two adjacent hydrogen atoms? A.CH4 B.H2O C.BH3 D.PH3 E.SF6

Q: Use VSEPR theory to predict the molecular geometry around the nitrogen atom in nitrite ion, NO2-.A.trigonal-planarB.tetrahedralC.trigonal-pyramidalD.T-shapedE.bent

Q: Use VSEPR theory to predict the molecular geometry of BrF5. A.tetrahedral B.see-saw C.trigonal-bipyramidal D.square-pyramidal E.octahedral

Q: Use VESPR theory to predict the molecular geometry around the carbon atom in formaldehyde, H2CO. A.linear B.bent C.trigonal-planar D.tetrahedral E.octahedral

Q: Use VSEPR theory to predict the molecular geometry around either carbon atom in acetylene, C2H2. A.linear B.bent C.trigonal-planar D.tetrahedral E.octahedral

Q: Use VSEPR theory to predict the molecular geometry of BrO3-.A.trigonal-pyramidalB.trigonal-planarC.bentD.T-shapedE.linear

Q: Use VSEPR theory to predict the electron-pair geometry and the molecular geometry of sulfur dioxide, XeF4. A.The electron-pair geometry is tetrahedral, the molecular geometry is tetrahedral. B.The electron-pair geometry is octahedral, the molecular geometry is tetrahedral. C.The electron-pair geometry is tetrahedral, the molecular geometry is octahedral. D.The electron-pair geometry is octahedral, the molecular geometry is square-planar. E.The electron-pair geometry is square-planar, the molecular geometry is tetrahedral.

Q: Use VSEPR theory to predict the electron-pair geometry and the molecular geometry of sulfur dioxide, SO2. A.The electron-pair geometry is trigonal-planar, the molecular geometry is trigonal-planar. B.The electron-pair geometry is trigonal-planar, the molecular geometry is bent. C.The electron-pair geometry is tetrahedral, the molecular geometry is bent. D.The electron-pair geometry is tetrahedral, the molecular geometry is linear. E.The electron-pair geometry is trigonal-bipyramidal, the molecular geometry is linear.

Q: Use VSEPR theory to predict the electron-pair geometry and the molecular geometry of boron tribromide, BBr3. A.The electron-pair geometry is trigonal-pyramidal, the molecular geometry is trigonal-pyramidal. B.The electron-pair geometry is trigonal-planar, the molecular geometry is trigonal-planar. C.The electron-pair geometry is trigonal-planar, the molecular geometry is bent. D.The electron-pair geometry is tetrahedral, the molecular geometry is trigonal-pyramidal. E.The electron-pair geometry is trigonal-pyramidal, the molecular geometry is t-shaped.

Q: Use VSEPR theory to predict the electron-pair geometry and the molecular geometry of nitrogen trichloride, NCl3. A.The electron-pair geometry is linear, the molecular geometry is linear. B.The electron-pair geometry is trigonal-planar, the molecular geometry is trigonal-planar. C.The electron-pair geometry is trigonal-planar, the molecular geometry is bent. D.The electron-pair geometry is tetrahedral, the molecular geometry is tetrahedral. E.The electron-pair geometry is tetrahedral, the molecular geometry is trigonal-pyramidal.

Q: Which of the following molecules or ions are likely to be free radicals: N2O, NO, and NO2? A.N2O only B.NO only C.NO2 only D.N2O and NO E.NO and NO2

Q: Which of the following species will have a Lewis structure most like that of IF4-?A.XeF4B.SO42-C.PF4+D.SF4E.IO4-

Q: The central atom in SF6 is surrounded by A.six single bonds and no lone pairs of electrons. B.six single bonds and one lone pair of electrons. C.six single bonds and two lone pairs of electrons. D.five single bonds, one double bond, and one lone pair of electrons. E.four single bonds, two double bonds, and no lone pairs of electrons.

Q: The central atom in the triiodide ion, I3-, is surrounded byA.two single bonds and no lone pairs of electrons.B.two single bonds and two lone pairs of electrons.C.two single bonds and three lone pairs of electrons.D.one single bond, one double bond, and one lone pair of electrons.E.two double bonds and one lone pair of electrons.

Q: What is the correct Lewis structure for IF3? A. B. C. D. E.

Q: What is the correct Lewis structure for SF4? A. B. C. D. E.

Q: When both of the electrons in a molecular bond originate from the same atom, the bond is called a(n) A.sigma bond. B.coordinate covalent bond. C.pi bond. D.metallic bond. E.ionic bond.

Q: Which of the following elements is most likely to form a molecular structure that disobeys the octet rule? A.B B.C C.N D.O E.F

Q: Which of the following elements is able to form a molecular structure that exceeds the octet rule? A.C B.B C.N D.F E.S

Q: Which of the following molecules or ions does not have one or more resonance structures?A.O3B.OCN-C.SO2D.H2COE.NO3-

Q: Which of the following are resonance structures for formate ion, HCO2-?A.1 and 2B.2 and 3C.3 and 4D.1, 3, and 4E.2, 3, and 4

Q: Which of the following are resonance structures for nitrite ion, NO2-?A.1 and 2B.2 and 4C.3 and 4D.1, 2, and 3E.2, 3, and 4

Q: One resonance structure for OCN- ion is drawn below. What is the formal charge on each atom?A.O atom = 0, C atom = 0, and N atom = 0B.O atom = 0, C atom = 0, and N atom = -1C.O atom = -1, C atom = 0, and N atom = 0D.O atom = -1, C atom = -1, and N atom = +1E.O atom = +1, C atom = 0, and N atom = -2

Q: One resonance structure for OCN- ion is drawn below. What is the formal charge on each atom?A.Cl atom = 0 and each O atom = 0B.Cl atom = 0 and each O atom = -1C.Cl atom = -1 and each O atom = 0D.Cl atom = +1 and each O atom = -1E.Cl atom = 0, one O atom = 0, one O atom = -1

Q: What is the formal charge on each atom in dichloromethane, CH2Cl2?A.C atom = 0, each H atom = 0, and each Cl atom = 0B.C atom = -2, each H atom = +1, and two Cl atoms = 0C.C atom = +4, each H = -1, and each Cl atom = -1D.C atom = +4, each H = +1, and each Cl atom = -1E.C atom = -4, each H = +1, and each Cl atom = +1

Q: The central atom in N2O is a nitrogen atom. This nitrogen atom is surrounded by A.two single bonds and two lone pairs of electrons. B.two single bonds and one lone pair of electrons. C.one single bond, one double bond, and one lone pairs of electrons. D.one single bond, one double bond, and one lone pair of electrons. E.two double bonds and no lone pairs of electrons.

Q: The nitrogen atom in cyanide ion, CN-, is surrounded byA.one single bond and three lone pairs of electrons.B.one double bond and one lone pair of electrons.C.one double bond and two lone pairs of electrons.D.one triple bond and one lone pair of electrons.E.one triple bond and no lone pairs of electrons.

Q: The central atom in SCl2 is surrounded by A.two single bonds and no lone pairs of electrons. B.two single bonds and one lone pair of electrons. C.two single bonds and two lone pairs of electrons. D.one single bond, one double bond, and no lone pairs of electrons. E.one single bond, one double bond, and one lone pair of electrons.

Q: Which of the following are possible Lewis structures for C2H6O? A.1 B.2 C.3 D.2 and 3 E.1, 2, and 3

Q: Which of the following is a correct Lewis structure for PH3? A. B. C. D. E.

Q: Which of the following is a correct Lewis structure for sulfate ion? A. B. C. D. E.

Q: Which of the following is a correct Lewis structure for nitrous acid, HNO2? A. B. C. D. E.

Q: Which of the following is a correct Lewis structure for sulfur dioxide, SO2? A. B. C. D. E.

Q: Which of the following molecules or ions will have a Lewis structure most like that of phosphorus trichloride, PCl3?A.ClO3-B.SO3C.CO32-D.BF3E.Cl2CO

Q: Which of the following molecules or ions will have a Lewis structure most like that of sulfur dioxide, SO2?A.NO2+B.CO2C.O3D.SCN-E.ClO2-

Q: If two or more species have the same number of electrons, resulting in similar Lewis structures, they are said to be ____. A.isoelectronic B.resonant structures C.ionic D.neutral E.covalent

Q: Which of the following molecules or ions are isoelectronic: SO3, NF3, NO3-, CO32-?A.SO3 and NF3B.NF3 and CO32-C.SO3, NF3 and CO32-D.SO3, NO3- and CO32-E.SO3, NF3, NO3-, and CO32-

Q: How many lone pair of electrons are assigned to the fluorine atom in HF? A.0 B.1 C.2 D.3 E.4

Q: How many lone pairs of electrons are assigned to the nitrogen atom in NCl3? A.0 B.1 C.2 D.3 E.4

Q: How many lone pairs of electrons are assigned to the carbon atom in carbon dioxide? A.0 B.1 C.2 D.3 E.4

Q: An arsenic atom has ____ valence electrons. A.3 B.5 C.6 D.8 E.33

Q: Which of the following statements is/are CORRECT? 1/ Chemical reactions result in the gain, loss, or rearrangement of valence electrons. 2/ For main group elements, the number of valence electrons equals eight minus the element's group number. 3/ Core electrons are not involved in bonding or in chemical reactions. A.1 only B.2 only C.3 only D.1 and 3 E.1, 2, and 3

Q: Which of the following statements is/are CORRECT? 1/ Ionic bonds form when one or more valence electrons are transferred from one atom to another. 2/ Covalent bonds involve sharing of electrons between atoms. 3/ In most covalently bonded compounds, electrons are NOT shared equally between the atoms. A.1 only B.2 only C.3 only D.1 and 2 E.1, 2, and 3

Q: Which combination of atoms is most likely to produce a compound with covalent bonds? A.K and Br B.Al and S C.S and Cl D.Sn and F E.Li and I

Q: Which combination of atoms is most likely to produce a compound with ionic bonds? A.B and C B.S and O C.N and F D.Si and Cl E.Mg and O

Q: Which of the following sets of quantum numbers is allowed?A.n = 2, = 1, = +1/2, ms = -1/2B.n = 3, = 2, = +1, ms = +1C.n = 4, = 1, = 0, ms = -1/2D.n = 4, = 3, = -1, ms = 0E.n = 5, = 2, = +2, ms = -1

Q: Which one of the following sets of quantum numbers is NOT allowed?A.n = 7, = 0, = 0, ms = +1/2B.n = 5, = 3, = -2, ms = +1/2C.n = 4, = 2, = 0, ms = -1/2D.n = 3, = 1, = -1, ms = +1/2E.n = 2, = 1, = 0, ms = 0

Q: What is the maximum number of electrons that can occupy the n = 3 shell? A.4 B.8 C.18 D.32 E.50

Q: What is the maximum number of electrons that can occupy the n = 5 shell? A.10 B.16 C.25 D.32 E.50

Q: How many electrons can be described by the quantum numbers n = 7, = 1? A.0 B.2 C.6 D.10 E.14

Q: How many electrons can be described by the quantum numbers n = 4, = 2, = 0? A.0 B.1 C.2 D.5 E.10

Q: How many electrons can be described by the following quantum numbers: n = 2, = 1, = -1, ms = -1/2?A.0B.1C.2D.3E.4

Q: Which of the following statements concerning the Pauli exclusion principle is/are CORRECT?1/ If two electrons occupy the same orbital they must have opposite spins.2/ No two electrons in an atom can have the same four quantum numbers.3/ Electrons with opposing spins are attracted to each other.A.1 onlyB.2 onlyC.3 onlyD.1 and 2E.1, 2, and 3

Q: Explain the difference between paramagnetic and ferromagnetic.

Q: Explain why the first ionization energy for oxygen is lower than that for nitrogen.

Q: Electron ________ is defined as the energy change for a process in which a gas phase atom acquires an electron.

Q: The f-block elements are also referred to as the ________ and actinides.

Q: As one moves horizontally from left to right across a period, the effective ________ charge increases, resulting in decreasing atomic radii.

Q: The element ________ has the following electron configuration: [Rn]5f127s2.

Q: ________ rule states that the most stable arrangement of electrons is that which contains the maximum number of unpaired electrons, all with the same spin direction.

Q: Place the following ions in order from smallest to largest ionic radii: K+, Na+, Mg2+, and Al3+. A.Al3+ < Mg2+ < Na+ < K+ B.Na+ < Mg2+ < Al3+ < K+ C.K+ < Mg2+ < Na+ < Al3+ D.K+ < Al3+ < Mg2+ < Na+ E.Mg2+ < Al3+ < Na+ < K+

Q: Place the following ions in order from smallest to largest ionic radii: Se2-, Sr2+, Y3+, and Br-.A.Se2- < Sr2+ < Y3+ < Br-B.Se2- < Br- < Sr2+ < Y3+C.Br- < Se2- < Y3+ < Sr2+D.Y3+ < Sr2+ < Br- < Se2-E.Sr2+ < Y3+ < Se2- < Br-

Q: Which group of the periodic table of elements forms only 2+ ions? A.group 1A B.group 2A C.group 1B D.group 7A E.group 8A

Q: Which elements have no affinity for electrons? A.transition metals B.s-block elements C.main group nonmetals D.noble gases E.semiconductors

Q: Which of the following elements has the most negative electron affinity? A.Cs B.Li C.O D.Cl E.F

Q: The change in energy for the following reaction is referred to as the ____ for boron.B(g) + e- B-(g)A.oxidation numberB.electron affinityC.electronegativity energyD.first ionization energyE.second ionization energy

Q: Rank F, Cl, and Br in order of increasing first ionization energy. A.F < Cl < Br B.Cl < F < Br C.Cl < Br < F D.Br < F < Cl E.Br < Cl < F

Q: For which one of the following elements is the second ionization energy over ten times larger than its first ionization energy? A.B B.N C.Li D.Ne E.Cu

Q: Which of the following chemical equations refers to the second ionization of Al?A.Al(s) + 2e- Al2-(s)B.Al+(g) Al2+(g) + e-C.Al(g) Al2+(g) + 2e-D.Al(s) Al+(s) + e-E.Al2+(g) + e- Al+(g)

Q: Which of the following statements is/are CORRECT? 1/ For any element, the second ionization energy is larger than the first ionization energy. 2/ Ionization energy is a positive value for all elements. 3/ Ionization energy increases down a group of the periodic table. A.1 only B.2 only C.3 only D.1 and 2 E.1, 2 and 3

Q: Place the following atoms in order of increasing atomic radii: K, Na, Be, and Li? A.Li < Na < K < Be B.Be < K < Na < Li C.Be < Li < Na < K D.K < Na < Li < Be E.Li < Be < Na < K

Q: Place the following atoms in order of increasing atomic radii: Se, Sb, Br, and Te. A.Br < Se < Te < Sb B.Se < Br < Sb < Te C.Se < Br < Te < As D.Sb < Te < Se < Br E.Te < Sb < Se < Br

Q: In general, atomic radii A.decrease down a group and remain constant across a period. B.decrease down a group and increase across a period. C.increase down a group and increase across a period. D.increase down a group and remain constant across a period. E.increase down a group and decrease across a period.