Supplemental Instruction
Iowa State University / Leader: / Erin Johnson
Course: / Chem 163
Instructor: / Windus/Bonaccorsi
Date: / 10/4/11
1. A covalent bond results from:
a) the electrostatic attraction between atoms where electrons are donated by one of the atoms
b) the electrostatic attraction between ions
c) the balance between attractive and repulsive forces between two atoms made by sharing two electrons.
2. Consider the energy-level diagram for an atom of hydrogen (H), and answer the following questions:
f) When an electron transitions from n = 3 to n = 2, is energy absorbed or released?
______
g) How much energy is involved in the transition of an electron from n = 3 to n = 2? Give your answer in joules (1 eV = 1.6023 ×10–19 J). Show your work.
h) What is the wavelength of the radiation in part g.? Show your work. Express your answer in nanometers: 1 m = 109 nm (or 1 nm = 10–9 m).
i) To which portion of the electromagnetic spectrum (shown on the last page of the test) does the radiation in part h. belong?
3. Consider a neutral atom of oxygen in its ground state. Write its full electronic configuration and fill in the orbital diagram (use the provided scheme).
Electronic configuration Orbital diagram
4. What is the wavelength in meters of the Ames radio station broadcasting at 105.1 MHz?
(1 MHz = 1 ×106 s–1)
5. Draw the Lewis dot structure of the following molecules.
Cl2 H2O
CF4 C2H4
N2
6. What do you predict be the formula of magnesium nitride, a compound of magnesium and nitrogen? ______
7. Which element has the greatest radius?
a) Na b) Mg c) S d) O
8. Fill in the blanks with the correct chemical name and whether the bond is covalent or ionic.
Formula Chemical Name Bond Type
a) NaBr ______
b) HCl ______
c) CO2 ______
9. What is the O–N–O angle in NO3/– ? Circle the correct answer.
a) 180° b) 120° c) 109.5° d) 270°
10. The VSEPR model predicts the O–O–O angle in ozone, O3, to be approximately:
a) 90° b) 109.5° c) 180° d) 120°
10. What is maximum number of electrons in the following?
a) 3d sublevel ______
b) Principle energy level n = 2 ______