Unit 2 Review Sheet
Atomic Theory
1. What is the difference between the law of multiple proportions and definite
proportions?
2. What are Dalton’s postulates?
3. Which of Dalton’s postulates are now known to be incorrect?
4. Describe Thomson’s experiment
5. What did Thomson conclude about the electron? (two things)
6. What was incorrect about Thomson’s model?
7. Describe Rutherford’s experiment and what he observed
8. What two things did Rutherford conclude about the atom?
9. What was missing from Rutherford’s model of the atom?
10. Draw Thomson’s model of the atom, Rutherford’s model of the atom, and
Bohr’s model of the atom- Label the negative charges and positive charges
Atomic Structure
1. A sample of hydrogen is 99% 1H, 0.8% 2H, and 0.2% 3H. What is its average
atomic mass?
2. Iodine is 80% 127I, 17% 126I, and 3% 128I. Calculate the average atomic mass of
iodine.
Atomic # = # of protons. Mass # = Atomic # + neutrons. Protons = electrons when
charge is zero. DO NOT LOOK AT THE MASS ON THE PERIODIC TABLE
Atomic #
Mass #
# p+
# e-
1) 17
2)
180
3)
4) 92
40
238
# n0
charge
19
0
71
109
38
46
86
206
5)
6)
Symbol
Pb4+
82
34
45
-2
7)
113
8) 21
42
48
49
0
31
P315
9)
10)
83
80
126
108
Ag
47
11)
12)
116
49
+3
13)
128
53
-1
14) 76
188
72
Waves and the Atomic Theory
1. Explain what occurs when energy is absorbed in a metal
2. What is the difference between the ground state and the excited state of the
electron?
3. Draw and label the parts of a wave. (including wavelength, amplitude, crest
and trough)
4. In each of the following pairs, circle the form of radiation with the LONGER
WAVELENGTH:
a. red light or blue light
b. microwaves or radiowaves
c. infrared radiation or red light
d. gamma rays or UV radiation
5. Circle the one with the lowest frequency:
a. yellow light or green light
b. x-rays or gamma rays
c. UV radiation or violet light
d. AM radio waves or FM radio waves
6. Circle the one with lowest energy
a. red light or blue light
b. microwaves or radiowaves
c. infrared radiation or red light
d. gamma rays or UV radiation
e. yellow light or green light
f. x-rays or gamma rays
g. UV radiation or violet light
h. AM radio waves or FM radio waves
7.
Show ALL equations, work, units in performing the following
calculations. (Use your electromagnetic spectrum)
C = λν
E = hν
8
C = 3.00 x 10 m/s
h = 6.626 2 x 10-34 J-s (or J/Hz)
1 eV = 1.602 x 10-19 J
8. What is the wavelength of a wave having a frequency of 3.76 x 1014 s1
?
9. What is the frequency of a 6.9 x 10-13 m wave?
10. What is the wavelength of a 2.99 Hz wave?
11. What is the wavelength of a 1.28 x 1017 Hz wave?
12. What is the frequency of a 2,600 cm wave?
13. What is the energy of a 7.66 x 1014 Hz wave?
14. 12. What is the frequency of a wave carrying 8.35 x 10-18 J of energy?
15. What is the energy of a 9,330 cm wave?
16. What is the wavelength of a 1.528 x 10-13 J wave?
17. HONORS What is the wavelength of a 1.32 x 10-6 eV wave?
Check Notes for Quantum Numbers