Chemistry 160 - Exam 4
Oxidation number =
# of valence electrons - (# shared e- + # of unshared e-)
How can we make lattice energy larger?
1. decrease distance b/w ions (smaller ions) 2. greater charge on ions
Electronegativity
Ability of atom to attract electrons away from other atoms in a compound
Born Haber Cycle
Allows for calculation of lattice energy - process of forming the compound from atoms in standard states
Magnetic properties: paramagnetism
Attracted to an external field (Not all 5 bond spots are full)
Metallic Behavior
Bottom left is most metallic Top right is least metallic
Which of the following is a covalent compound? a. Na2O b. CaCl2 c. Cl2O d. MgBr2
Cl2O
4 Exceptions to electron configuration
Cr, Mo, Cu, Ag
Least electronegative element
Cs
Most electronegative element
F
Which of the following atoms/ions will have the smallest radius? a) K+ b) K c) Ca2+ d) Ca e) Rb+
a) K+
Nonmetal oxides act like aN
acid
Which of the following elements will form a cation with a 2+ charge? a) Si b) Sr c) Ga d) Cs e) S
b) Sr
Which of the following compounds will have the highest lattice energy? a. RbBr b. LiF c. KCl d. LiCl e. RbCl
b. LiF
Metal oxides act like a
base
In which of these substances are the atoms held together by polar covalent bonding? a. SrCl2 b. CsCl c. ClF d. CaF2 e. S8
c. ClF
Which of the following elements is the most electronegative? a. O b. Li c. F d. I e. Cl
c. F (up and right)
Identify the element of Period 2 that has the following successive ionization energies, in kJ/mol 1E1, 1314 1E2, 3389 1E3, 5298 1E4, 7471 1E5, 10992 1E6, 13329 1E7, 71345 1E8, 84087 a. Li b. B c. O d. Ne e. none of these is correct
c. O
Which of the following contains ionic bonding? a. CO b. SrF2 c. Al d. OCl2 e. HCl
c. SrF2
Electronegativity is a measure of: a) the energy needed to remove an electron from an atom b) the energy released when an electron is added to an atom c) the magnitude of the negative charge on an electron d) the attraction by an atom for electrons in a chemical bond e) the magnitude of the negative charge on a molecule
d) the attraction by an atom for electrons in a chemical bond
Which of the following elements has the largest atomic size? a. Rn b. Ca c. Po d. Ba e. S
d. Ba
Exothermic reaction
e- is on the left side of the arrow & (g) + (g) = s
Endothermic reaction
e- is on the right side of the arrow
Which of the following atoms will be diamagnetic? a. Cr b. Ru c. Fe d. Pt e. Cd
e. Cd - [Kr]5s2(4)d10
Select the element with the greatest metallic character a. Li b. Ca c. Al d. Pb e. Cs
e. Cs
Electron Affinity
energy is required when a gaseous atom adds an e-
Ionization Energy
energy required to remove an electron *greatest at top right *lowest at bottom left
lattice energy
energy which holds ions together
Lattice Energy
k((Q+ x Q-)/(d))
Anions (-) are _________ than parent atoms. Electrons are ________ from the outer level.
larger, added
Metallic bond
metals with metals
Magnetic properties: Dimagnetic
not attracted to the field (All 5 bond spots are full)
Covalent Bond
sharing of e- between two or more nonmetals
The effective nuclear charge for an atom is less than the actual nuclear charge due to
shielding
Cations (+) are _________ than parent atoms. Electrons are ________ from the outer level.
smaller, removed
Ionic bonds
transfer of e- between metal and nonmetal
Determining Formal Charge
# Valence - # Lone e - # of bonds
