Unit 2 Practice Test ANSWER
Name:______/ Date:______Multiple Choice:
1. Which atomic model(s) take into account the wave-like properties of electrons?
I) Thomson’s raisin-bun model III) Bohr’s planetary model
II) Rutherford’s electron cloud model IV) the quantum mechanical model
a) IV only b) III and IV c) II and III d) II, III, and IV
2. Which scientist first postulated (suggested) a nuclear atom?
a) Rutherford b) Dalton c) Bohr d) Thomson
3. The energy of a photon is proportional to which of the following?
a) its momentum b) its velocity c) its amplitude d) its wavelength
4. Which of the following is true about an orbital’s boundary?
a) an electron can not go past an orbital’s boundary
b) an electron spends more than 95% of its time travelling along the orbital’s boundary
c) an electron spends more than 95% of its time travelling within the orbital’s boundary
d) an electron spends more than 95% of its time travelling outside the orbital’s boundary
5. Which of the following is the correct orbital box diagram for a neutral, ground state nickel atom?
6. How many orbitals can have the quantum numbers n = 3 and l = 2?
a) 1 b) 3 c) 5 d) 7
7. The maximum number of electrons that can have the quantum levels n = 2 and l = 1:
a) 2 b) 3 c) 6 d) 8
8. Which of the following orbitals can have a magnetic quantum number of +2?
a) 2s b) 2p c) 3p d) 3d
9. What is the condensed electron configuration for a ground state sulfide ion, S2–?
a) [Ar] b) [Ne] 3s2 3p4 c) [Ne] 3s2 3d2 3p4 d) [Ne] 3s2 3p6
10. Which of the following will have the smallest ionic radius?
a) Si 4+ b) Si c) Si 4- d) Na1+
11. Which of the following atoms has the highest electronegativity?
a) Ar b) Mg c) Ca d) P
12. The ionization energies for an unknown element are:
IE1 = 5.4 eV IE2 = 8.4 eV IE3 = 15.7 eV IE4 = 85.4 eV IE5 = 98.6 eV
Which is the most probable electron configuration for a neutral atom of this element?
a) 1s22s22p63s23p64s1 c) 1s22s22p63s23p64s2
b) 1s22s22p63s23p6 d) 1s22s22p63s23p1
13. Based on VSEPR theory, what is the predicted molecular shape of SCℓ 2?
a) linear b) T- shaped c) tetrahedral d) bent (V-shaped)
14. Which of the following is/are non-polar molecules?
I) NCℓ3 II) BF3 III) PCℓ5
a) I and II only b) II and III only c) II only d) I, II and III
15. Arrange the species in order of decreasing H – N – H bond angle:
16. Which compound is expected to have the lowest melting point?
a) CsF b) RbF c) KF d) NaF
17. The H – O – H bond angle in water is:
a) 109.5 º b) < 109.5 º c) > 109.5 º d) 180 º
18. Identify all type(s) of inter-molecular attractions that exist in a pure sample of NH3:
I) ion – ion attractions III) hydrogen bonds
II) dipole – dipole attractions IV) London dispersion forces
a) I and IV b) II and IV c) II, III and IV d) IV only
19. Which of the following is/are network solid(s)?
a) graphite b) diamond c) SiO2 in quartz d) all of the above
20. What kind of hybrid orbitals are utilized by the carbon atom in CF4 molecules?
a) sp1 b) sp3 c) sp2 d) sp3d
MULTIPLE CHOICE ANSWER AREA:
Put the best answer in the box below for each multiple choice question. Use capital letters only.
1 A / 2 A / 3 D / 4 C / 5 A / 6 C / 7 C / 8 D / 9 D / 10 A11 D / 12 A / 13 D / 14 C / 15 B / 16 A / 17 B / 18 C / 19 D / 20 B
Short answer:
1. Explain in what way that Rutherford’s model of an atom violates classical physics (Comm, 2m)
According to classical physics:
• -e in orbit around a nucleus continually accelerate in a curved path
• Thus, they should continuously emit electromagnetic radiation (photons)
• The e- then would lose energy, slow down and spiral into the nucleus in a very short time (i.e. atoms cannot exist)
2. a. Use simple valence bond theory along with hybridization to show CO2 bonding.
(8 marks Comm.)
Your answer should include:
¨ a. Lewis structure ¨ b. Diagram of valence shell energy level orbitals
¨ c. Diagram of overlapping orbital ¨ d. Label of types of bonds (s or p) formed.
3. Complete the following table (App, 10m)
Molecule / Lewis Dot Structure / VSEPR Notation / Hybridization / Hybridization DevelopmentCH3Cl / AXnEm Notation
e- geometry
Hybridization
HONH2 / AXnEm Notation
e- geometry
Hybridization
4. Determine the hybridization and the bond angle at the labelled carbons and oxygen in ibuprofen, the active ingredient in Advil and Tylenol (App, 5 marks]
Atom / Hybridization / Bond AngleC1
C2
C3
O1
O2
Ibuprofen
5. Complete the following table AND provide your reasons below the table (4m, Comm; 4m App)
Molecules / Types of IMF present / Rank in bp (1 being the highest bp)C2H4
CH4
Ne
H3C-O-CH3