Enrichment Directions: Fill in the 12 steps in the decay of U-235 in the diagram below. Begin with U-235 and finish with an
isotope of lead. The particles emitted in each step are listed below. Use the periodic table to find information about
mass numbers, atomic numbers, and chemical symbols. Place the correct symbol in the space corresponding to the
correct mass number and atomic number.
Step
Particle emitted
235
1
Alpha
2
Beta
231
3
Alpha
227
4
Copyright Glencoe McGw-Hill, division of The Mcww. Him Companies,
Alpha
5
Beta
223
6
Alpha
Mass Number
219
7
Alpha
215
8
Alpha
9
Beta
211
10
Alpha
207
11
Beta
12
Stable
203
81 82 83 84 85 86 87 88 89 90 91 92 93
Atomic Number
1. What nucleus is the final product?