Practice worksheet for understanding nuclear radiation types and balancing decay equations.

Let’s go step by step through each section of the worksheet. We’re balancing nuclear equations — that means making sure the total mass numbers (top numbers) and atomic numbers (bottom numbers) are equal on both sides of the arrow.

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Section 1: Alpha, Beta, or Gamma?

We need to figure out what particle is emitted based on how the parent nucleus changes into the daughter nucleus.

Recall:
- Alpha decay: emits helium-4 → ⁴₂He → mass decreases by 4, atomic number decreases by 2.
- Beta decay: emits electron → ⁰₋₁e → mass stays same, atomic number increases by 1.
- Gamma decay: emits gamma ray → ⁰₀γ → no change in mass or atomic number (just energy release).

Now solve each:

1. ⁵⁴₂₇Co → ⁵⁰₂₅Mn + ?
Mass: 54 → 50 → difference = 4
Atomic: 27 → 25 → difference = 2
→ That’s alpha decay → ⁴₂He

2. ²³⁶₉₄Pu → ²³²₉₂U + ?
Mass: 236 → 232 → diff = 4
Atomic: 94 → 92 → diff = 2
→ Alpha → ⁴₂He

3. ⁸₃Li → ₄Be + ?
Mass: 8 → 8 → no change
Atomic: 3 → 4 → increased by 1
→ Beta decay → ⁰₋₁e

4. ⁶₂₇Co → ⁶⁰₂₇Co + ?
Same element, same mass, same atomic number → just energy released
→ Gamma → ⁰₀γ

5. ²²²₈₈Ra → ²¹⁸₈₆Rn + ?
Mass: 222 → 218 → diff = 4
Atomic: 88 → 86 → diff = 2
→ Alpha → ⁴₂He

6. ²³⁴₉₀Th → ²³₉₁Pa + ?
Mass: same (234)
Atomic: 90 → 91 → +1
→ Beta → ⁰₋₁e

✔ Section 1 Answers:
1. ₂He
2. ⁴₂He
3. ⁰₋₁e
4. ⁰₀γ
5. ₂He
6. ⁰₋₁e

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Section 2: Complete alpha-decay equations

Alpha decay always emits ⁴₂He. So we subtract 4 from mass and 2 from atomic number to find the daughter nucleus.

7. ²³₇₆Os → ? + ⁴₂He
Daughter mass: 203 - 4 = 199
Daughter atomic: 76 - 2 = 74 → W (tungsten)
→ ¹⁹⁹₇W

8. ²⁴₆₄Gd → ? + ⁴₂He
Mass: 249 - 4 = 245
Atomic: 64 - 2 = 62 → Sm (samarium)
→ ²⁴⁵₆₂Sm

9. ²⁵⁶₁₀₃Lr → ? + ⁴₂He
Mass: 256 - 4 = 252
Atomic: 103 - 2 = 101 → Md (mendelevium)
→ ²⁵²₁₀₁Md

10. ²³⁷₉₃Np → ? + ⁴₂He
Mass: 237 - 4 = 233
Atomic: 93 - 2 = 91 → Pa (protactinium)
→ ²³³₉₁Pa

✔ Section 2 Answers:
7. ¹⁹⁹₇₄W
8. ²⁴⁵₆₂Sm
9. ²⁵²₁₀₁Md
10. ²³³₉₁Pa

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Section 3: Complete beta-decay equations

Beta decay emits ⁰₁e. Mass stays same, atomic number increases by 1.

11. ²₂₆Fe → ? + ₋₁e
Mass: 52 (same)
Atomic: 26 + 1 = 27 → Co (cobalt)
→ ⁵²₂₇Co

12. ²⁴₁₁Na → ? + ⁰₋₁e
Mass: 24
Atomic: 11 + 1 = 12 → Mg (magnesium)
→ ²⁴₁₂Mg

13. ⁴⁵₂₀Ca → ? + ⁰₋₁e
Mass: 45
Atomic: 20 + 1 = 21 → Sc (scandium)
→ ⁴⁵₂₁Sc

14. ³⁵₁₅P → ? + ⁰₋₁e
Mass: 35
Atomic: 15 + 1 = 16 → S (sulfur)
→ ³⁵₁₆S

✔ Section 3 Answers:
11. ⁵²₂₇Co
12. ²⁴₁₂Mg
13. ⁴⁵₂₁Sc
14. ³⁵₁₆S

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Final Answer:

Section 1:
1. ⁴₂He
2. ⁴₂He
3. ⁰₋₁e
4. ⁰₀γ
5. ⁴₂He
6. ⁰₁e

Section 2:
7. ¹⁹⁹₇W
8. ²⁴⁵₆₂Sm
9. ²²₁₀₁Md
10. ²³³₉₁Pa

Section 3:
11. ²₂₇Co
12. ²⁴₁₂Mg
13. ⁵₂₁Sc
14. ³⁵₁₆S