Quantum Mechanics and Planar Nodes

Chem1101

Sample Quiz 1

Last update: 25/3/13

1. What is the decay product resulting from the emission of an alpha particle from a)
207 82

210 85

At ?

Pb

b)

210 86

Rn

c)

206 83

Bi

d)

206 81

Tl

e)

206 85

At

2. Which nuclide is needed to balance the following nuclear reaction?
235 92

U +
b)
138 53

1 0

n  ? +
c)
137 53

96 39

1 Y + 30n

a)

139 53

I

I

I

d)

136 53

I

e)

135 53

I

3. Only one of the following isotopes of strontium undergoes radioactive decay by – emission. Which one is it? a)
83 38

Sr

b)

86 38

Sr

c)

87 38

Sr

d)

88 38

Sr

e)

90 38

Sr

4. For which one of the following atoms or ions would the 2s and 2p orbitals have the same energy? a) O2– b) H c) He d) Li+ e) F6+

5. Which of the following electron excitations of the hydrogen atom requires light of the shortest wavelength? a) b) c) d) e) n = 2 to n = 3 n = 3 to n = 4 n = 4 to n = 20 n = 5 to n = 100 n = 4 to n = 1000

6. Which one of the following electron configurations is not valid? a) 1s2 2s2 2p2 b) 1s2 2s2 2p6 3s2 3p6 c) 1s2 2s2 2p6 3s2 3p2 d) 1s2 2s2 2p6 3s2 3p3 e) 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p8

7. What is the specific activity (in Bq g–1) of the nuclide 1.6 seconds? a) 2.9  1021 b) 3.3  1021 c) 3.6  1021

90 35

Br , whose half-life is

d) 1.0  1021

e) 2.6  1023

8. Which one of the following sets of quantum numbers is valid? n a) b) c) d) e) 3 1 3 1 5 l 1 1 3 1 4 ml (or m) 0 0 –2 1 3 ms (or s) 0 –½ +½ 0 +½

9. Which of the following lobe depictions of atomic orbitals is the best representation of a 1s orbital? The white and grey shading represent different phases of the wavefunction.

a)

b)

c)

d)

e)

10. How many nodes does a 5s atomic orbital have? a) b) c) d) e) 0 planar nodes and 0 spherical nodes 3 planar nodes and 2 spherical nodes 1 planar node and 1 spherical node 0 planar nodes and 4 spherical nodes