Unit 3Chapters 6, 7, 8, and 9

Electronic structure of atoms:

Electromagnetic Radiation:

Chapter 6: The electronic structure of atoms

Yellow light has a wavelength of 589 nm. What is the frequency of this radiation?

Example Problem

E = hv

Calculate the energy of one photon of yellow light with a wavelength of 589 nm.

Light and Energy

Electron Configuration

Condensed Electron Configurations

Electron Configuration of Ions

1) Which of the following pairs are isoelectronic?

a) Kr-, Br+

b) F-, Na+

c) Sc, Ti-

d) Be2+, Nee) Cs, Ba2+

Example Problems

2) Which of the following electron configurations represents an atom in an excited state?

a) 1s22s22p5

b) 1s22s22p53s2

c) 1s22s22p63s1

d) 1s22s22p63s23p5

e) 1s22s22p63s23p64s1

The periodic table:

Chapter 7: Periodic Properties of Elements

Effective Nuclear Charge

Sizes of Atoms and Ions

Ionization Energy

Electron Affinity

Which of the following properties generally decreases from left to right across a period?

(A) Electronegativity

(B) Electron affinity

(C) Atomic number

(D) Atomic Radius

(E) Maximum value of oxidation number

Example Problems

Which of the following explains why the Cl- ion is smaller than the S2- ion.

(A) Cl- has a more massive nucleus than S2-

(B) Cl- has a higer electronegativity than S2-

(C) Cl- has a greater nuclear charge than S2-

(D) Cl- has a greater number of electrons than S2-

(E) Cl- has more nucleons than S2-

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Chemical Bonds

Lewis Symbols

Octet Rule

Ionic Bonding

Lattice Energy

Covalent Bonding

Drawing Lewis Structures

Bond Length

Polar and Non-polar bonds

Some molecules have more than one possible correct Lewis structure.

Lewis Structures Cont.

Resonance Structures

Exceptions to the octet rule

Strengths of Covalent Bonds

Chapter 9: Molecular Geometry

Molecular Shapes and Polarity

Which of the following molecules has the shortest bond length?

(A) N2

(B) O2

(C) Cl2

(D) Br2

(E) I2

Example Problems

Which of the following molecules is non-polar?

(A) HCN

(B) NH3

(C) SO2

(D) NO2

(E) PF5

Of the following compounds which is most ionic?

(A) SiCl4

(B) BrCl

(C) PCl3

(D) Cl2O

(E) CaCl2