Honors Chemistry: Atomic Theory/Nuclear Test Review
Particles of the Atom
 proton, neutron, electron…nucleons?
 charges, location, masses
 mass number, atomic number
 charged atoms = ions
Isotopes
 same element (protons), different masses
(neutrons)
 Complete Atomic Designation
 Average Atomic Mass
 radioactive isotopes
o half-Life
 nuclear transmutation reactions
o decay particles: alpha, beta, gamma,
positron
o emission/decay v. bombardment
 fission v. fusion
 E = mc2
History of the Atom (what resulted from each model?)
 Greeks
 John Dalton
o Atomic Theory (know postulates)
 J.J. Thomson
o cathode ray tube
o plum-pudding model
 Rutherford
o gold foil experiment
 Chadwick
o discovered neturons
 Bohr
o planetary model of the atom
Name_______KEY_______________

Light


Quantum Mechanical Model
o electron cloud model
o orbitals
ground state v. excited state
o absorption of energy  light emission
(emission spectrum)
characteristics of waves
o wavelength, frequency, crest, trough,
amplitude
o How does wavelength change v. frequency?
v. energy?
…frequency v. energy?

calculations
o c = λf, where c = 3.0 x 108 m/s
o E = hf, where h = 6.63 x 10-34 J s
Electron Configuration
 energy levels, types of orbitals, filling order (use
Periodic Table)
 shorthand notation (using noble gases)
 orbital diagrams (filling order)
o aufbau Principle
o Hund’s Rule
o Pauli Exclusion Principle
 valence electrons vs. kernel (core) electrons
 ion formation (losing/gaining e-) and octet rule
Periodic Table
 s-block, p-block, d-block, f-block
 charges (+1, +2,…..2-, 1-)
Atomic Structure Review Questions
1. Using your vocabulary and your notes, fill in the following blanks.
Protons are POSITIVELY charged particles in the NUCLEUS of an atom. The protons have a mass of
approximately ONE AMU. The number of protons in the nucleus, also called the ATOMIC NUMBER, is
responsible for determining the type of atom, or the ELEMENT. The NEUTRONS are also in the nucleus with
the protons, together their sum is the MASS NUMBER. Neutrons are almost equal in mass to the protons and
are NEUTRAL in charge. NEUTERONS are responsible for creating isotopes. Outside the nucleus are the
ELECTRONS which can be gained or lost to produce IONS. Positively charged ion are called CATIONS, while
negatively charged ions are called ANIONS.
2. Using your vocabulary and your notes, complete the following table.
Scientist
Dalton
Experiment/Observation
Law of multiple proportions, atoms are
indivisible, all atoms of an element are
the same
Discovery or Major Contribution
Atomic Theory
Model
Cathode ray tube
Electrons and + charges
(plum-pudding model)
Gold-Foil Experiment
+ Nucleus;
Atom is mostly empty space.
Electrons have only specific energy levels
and distances from the nucleus that are
allowed.
Electrons in ORBIT at fixed
distances from nucleus
(planetary model)
Math / probability
s-, p-, d-, f-orbitals
Quantum Mechanical Model
Thomson
Rutherford
Bohr
Various
3. The element Chemistrium (Ch) has 2 varieties, Ch-110 and Ch-112. Ch-110 has a % abundance of 73%. Find the
average atomic mass of Ch.
AAM = (% A)(mass A) + (% B)(mass B)
AAM = (0.73)(110 amu) + (0.27)(112 amu)
AAM = 80.3 amu + 30.24 amu
AAM = 110.54 amu
4. The element rubidium (Rb) has an average atomic mass of 85.468 amu. Rubidium has two common isotopes, 85Rb
and 87Rb. The average atomic mass of 85Rb is 85.00 amu and the abundance of is 72.2%, what is the average atomic
mass of 87Rb?
AAM = (% A)(mass A) + (% B)(mass B)
85.468 amu = (0.722)(85.00 amu) + (0.278)(x amu)
24.098 = 0.278 x
x = 86.68 amu = 87Rb
5. Complete the following table:
Atomic #
Protons
Neutrons
Electrons
Mass #
Net Charge
23
23
28
18
51
5+
Complete
Atomic
Designation
51
V 5+
23
209
83
83
126
80
209
3+
83
178
72
72
106
68
178
4+
Bi 3+
Hf
4+
72
6. Complete the chart below concerning the different types of radioactive decay:
alpha
composition
helium nucleus
beta
fast-moving
electron
gamma
positron
high-energy wave
+ charged e-
0
symbol
charge
2+
high
1~0 amu
(0.00054 amu)
low
medium-low
1+
~0 amu
(0.00054 amu)
low
approx. mass
~ 4 amu
approx. energy
penetrating power
low
moderate
very high
moderate
0 amu
7. Complete the following transmutation reactions:
e. Americium-240 decays by alpha emission and
a. Radon-225 decays by beta emission:
225
86
Rn 
0
1
e 
225
87
then beta emission:
240
95
Fr
b. Samarium-147 decays by alpha emission:
147
62
c.
Sm 
4
2
He 
143
60
f.
Tm  10 e 
186
68
Al 
0
1
e 
25
12
He 
0
1
e
236
94
Pu
An alpha particle bombards an phosphorus-32
32
15
P
4
2
He 
1
0
n
35
17
Cl
g. An alpha particle bombards a fluorine-19 atom,
Er
producing a new atom and a proton:
d. Aluminum-25 undergoes positron emission:
25
13
4
2
atom, producing a new atom and a neutron:
Nd
Thulium-186 undergoes electron capture:
186
69
Am 
19
9
Mg
F 
4
2
He 
1
1
p
22
10
Ne
8. What is the definition of half-life? The time it takes for half of a radioactive element to decay
9. The half-life of a substance is 9.7 ms. How long will it take for 25 % of the original amount to remain?
100%  50%  25% = 2 half-lives
9.7 ms x 2 half-lives = 19.4 ms  19 ms
10. If you originally had 100. g of a substance, how much will you have left after 4 half-lives? After 5 half-lives?
100. g  50.0 g  25.0 g  12.5 g  6.25 g  3.13 g
11. A given substance has a half-life of 2.0 x 109 years. If you buy 150. g of this substance, how much will be left after
12,000,000,000 years?
12 x 109 yr / 2.0 x 109 yr = 6 t1/2
150 (1/2)6 = 2.3438  2.34 g
12. What is the half-life of a substance, if after 5000 years, a 1800 g sample now masses 450 g?
1800 g  900 g  450 g = 2 t1/2
5000 yr / 2 = 2500 yr for every t1/2
13. The mass of a thorium-232 nuclide is 232.011 amu. What is the mass defect (in amu)?
90 p  (1.00728 amu)  142 n0 (1.00866 amu)  233.88492 amu
mass defect  233.88492 amu  232.011 amu  1.87392 amu
14. Calculate the energy produced by the thorium-232 nuclide (in J).

  1 kg 
1g
 
 
1.87392 amu 
23
6
.
02
x
10
amu
1000
g



3.11282 x 1027 kg
2
E  mc  3.11282 x 10
2
27
m

kg  3 x 108  
s

2.80154 x 10 10 J
15. Draw two light waves: one with a long wavelength and one with a short wavelength.
Wavelength is inversely related to frequency and energy. So, a wave with a long wavelength would have both
a lower frequency and a lower energy. The wave with a short wavelength would have a comparably larger
frequency and energy. Remember that frequency and energy are directly related.
Compare the frequency and energy of your two waves.
16. The following diagrams show energy changes within an atom as an electron either absorbs or emits energy.
a. Which diagram shows energy being absorbed?
Diagram I: energy is absorbed, causing an e- to be
promoted from level 2 to level 5 (excited)
…emitted as light (given off)?
b.
e-
e-
Diagram II: light is emitted as the e- falls from level 4
back down to level 2
I.
c.
II.
Which diagrams shows the greatest change in energy?
Diagram I: the difference in energy from levels 2 to 5 is
greater than from levels 4 to 2.
d. Assuming light is involved in both energy changes,
which diagram illustrates light with a longer wavelength? Why?
Diagram II: wavelength is inversely related to energy, so because this diagram has the smaller energy
change, its resulting wave will have a longer wavelength
17. A photon of light has a wavelength of 3.20 x 103 cm. Find… λ = 3.20 x 101 or 32 m (must use m for these eq.)
a. the frequency of the radiation.
c = λ· f
b. the energy of the photon.
E = h·f
8
3.0 x 10 m/s = 32 m (f)
E = 6.63 x 10-34 J·s (9,375,000 Hz)
f = 9.4 x 106 Hz
E = 6.2 x 10-27 J
18. Write the longhand and shorthand electron configurations for the following atoms: valence e- in red
Longhand
Shorthand
a) boron
B = 1s22s22p1
B = [He] 2s22p1
b) nitrogen
N = 1s22s22p3
N = [He] 2s22p3
c) cadmium
Cd = 1s22s22p63s23p64s23d104p65s24d10
Cd = [Kr] 5s24d10
d) sodium ion
Na+ = 1s22s22p6
Na+ = [He] 2s22p6 or [Ne]
e) phosphide ion
P3- = 1s22s22p63s23p6
P3- = [Ne] 3s23p6 or [Ar]
19. For 18a and 18b, draw an orbital diagram below. You can use boxes for the orbitals and arrows for the electrons.
18a.
18b.
20. Look at your periodic table. For each of the following elements, answer the following:
a. How many valence electrons does this element have?
b. …core electrons?
c. How many electrons would this element gain or lose to become more stable? Specify gain or lose.
d. What charge would this element have after following the octet rule?
H
N
O
Br
Mg
Kr
a.
1
5
6
7
2
8
b.
0
2
2
28
10
c.
loses 1e-
gains 3 e-
gains 2 e-
gains 1 e-
loses 1e-
d.
1+
3-
2-
1-
2+
28
neither gains
nor loses
0