Week 6 Worksheet

Week 6 Worksheet
1. How many protons and neutrons are in: 55Mn, 201Hg, potassium-39, barium-141?
55Mn,
Number of protons: 25
Number of neutrons: 55 - 25 = 30
201Hg,
Proton: 80
Neutrons: 201-80 = 121
Potassium-39:
Protons: 19
Neutrons: 39 - 19 = 20
Barium-141:
Protons: 56
Neutrons: 141 - 56 = 85
2. How many protons and neutrons are in 60Co, 238U, thorium-232, radon-220?
60Co
Protons: 27
Neutrons: 60-27 =33
238U
Protons: 92
Neutrons: 238-132 = 146
thorium-232
Protons: 90
Neutrons: 232-90 = 142
radon-220
Protons: 86
Neutrons: 220-86 = 134

3. Write balanced equations for: bismuth-214 undergoes beta decay, plutonium-242
emits alpha radiation, selenium-81 undergoes beta decay, uranium-235 undergoes alpha
decay, 11C emits a positron, O-15 undergoes electron capture
Plutonium-242 emits alpha radiation:
Bi83
214 → Po+ e1
0
84
214
Plutonium-242 emits alpha radiation:
Pu94
238 → U92
238 + He2
4
Selenium-81 undergoes beta production
Se34
81 → Br+ e1
0
35
81
Uranium-235 undergoes alpha decay:
U92
235 → Th+ He2
4
90
231
11C emits a positron:
C6
11 → β+ e1
0
5
1 1
O-15 undergoes electron capture:
O+ e1
0 → N7
15
8
15
4. Write balanced equations for: 241Am emits alpha radiation, chromium-51 undergoes
electron capture, 99Tc emits a gamma particle, fluorine-18 emits a positron, 124Sb emits a
beta particle.
241Am emits alpha radiation:
Am → Np97
237
95
241 + He2
4
Chromium-51 undergoes electron capture,
Cr+ e1
0
24
51 → Mn25
51
99Tc emits a gamma particle:
Tc →43
99 m Tc+ γ43
99 m

Fluorine-18 emits a positron
F → O+ e1
0
8
18
9
18
124Sb emits a beta particle.
Sb → Te+ β−1
0
52
124
51
124
5. What kind of nuclear decay/capture is each of the following (write equations and
name process): I-131 to Xe-131, Ra-226 to Rn-222, Rb-81 to Sr-81, Hg-201 to Tl-201,
Th-231 to Ra-227, N-13 to C-13, Pu-242 to Pu-242, Be-7 to Li-7
6. What kind of nuclear decay/capture is each of the following (write full equations and
name process):
216Rn  42He + ____ alpha decay
___  42He + 239Bk alpha decay
40K  40Ca + ___
40K + ___  40Ar
40K  40Ar + ___
60Co  60Co + ___
7. What kind of decay, and why, would you expect from each of the following? Note that
if you look these up on the internet, you may find that each decays by more than one
mechanism. The only correct/acceptable answers will be those that could be reasonably
predicted based upon nuclear makeup.
35S