Name: ______Date: ______
Chemistry 12U – Sample Questions
Structures and Properties
1. List five atoms that would be isoelectronic with F-
2. Draw an energy level diagram for Fe 2+
3. Give the shorthand electron configuration for the following
a) Calcium ion :
b) Hg 2+ :
c) Mo2+ :
4. Describe Bohr’s contribution to the model of the atom. What empirical (experimental) evidence was it based on and what was the limitation to his model?
5. An electron of hydrogen is excited to n = 5 and drops down to n = 4 to release a photon of light of a certain wavelength. Explain why this drop was not one that was confirmed by the spectroscopic observations. Calculate the wavelength of the photon. (RH = 1.10 x 107 m-1 )
6. Why does OF6 not exist whereas SF6 does?
7. For each of the following, draw the Lewis structures, and then draw and name the VSEPR diagrams. State if each is polar or not and provide the reason why.
a) SO2 b) XeF4 c) ClF3 d) b) KrOF4 e) ClO4-
- At room temperature methanol (CH3OH) is liquid whereas bromine (Br2) is in its gaseous form. Why? Draw the structure of each and explain your choice by including all contributing factors.
9. Choose only three of the following four questions.
a) Why are salts such as sodium chloride brittle?
b) Why is ice so soft compared to diamond?
c) Why do metals conduct electricity?
d) Briefly describe a technology that resulted from quantum theory.
Selected Answers
1) N3-, O2-, Ne, Na+, Mg2+, Al3+
3) Consider their energy Level diagrams, Re2+ has 5 unparied e- whereas Co2+ only has 3, Re2+ is more paramagnetic.
4) a) [Ar] b) [Xe] 4f14 5d10 c) [Kr] 4d4
6) 4040 nm, it is in the infrared range
7) Oxygen cannot have an expanded octet due to the absence of a d shell in the second principal quantum level. S being in the third level does have a d shell to place the extra 4 electrons.