Chemistry worksheet focusing on nuclear equations and decay types.

Let’s go through each nuclear equation one by one. We’ll balance the mass numbers (top) and atomic numbers (bottom), then identify the type of decay.

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1. ²¹⁴₈₄Po → ²¹⁰₈₂Pb + ?

Mass: 214 = 210 + ? → ? = 4
Atomic: 84 = 82 + ? → ? = 2
→ That’s an alpha particle: ⁴₂He
Type: alpha

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2. ²²²₈₆Rn → ? + ⁴₂He

Mass: 222 = ? + 4 → ? = 218
Atomic: 86 = ? + 2 → ? = 84 → Element 84 is Po
→ Product: ²¹⁸₈₄Po
Type: alpha

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3. ²³⁰₉₀Th → ²²⁶₈₈Ra + ?

Mass: 230 = 226 + ? → ? = 4
Atomic: 90 = 88 + ? → ? = 2
→ Alpha particle: ⁴₂He
Type: alpha

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4. ²¹⁴₈₂Pb → ? + ⁰₋₁e

This is beta decay — electron emitted.
Mass: 214 = ? + 0 → ? = 214
Atomic: 82 = ? + (-1) → ? = 83 → Element 83 is Bi
→ Product: ²¹⁴₈₃Bi
Type: beta

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5. ²²⁶₈Ra → ? + ⁴₂He

Mass: 226 = ? + 4 → ? = 222
Atomic: 88 = ? + 2 → ? = 86 → Element 86 is Rn
→ Product: ²²²₈₆Rn
Type: alpha

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6. ²³⁹₉₃Np → ? + ⁰₋₁β

Beta decay again.
Mass: 239 = ? + 0 → ? = 239
Atomic: 93 = ? + (-1) → ? = 94 → Element 94 is Pu
→ Product: ²³⁹₉₄Pu
Type: beta

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7. ? → ²³⁴₉₀Th + ⁴₂He

Reverse of alpha decay.
Mass: ? = 234 + 4 = 238
Atomic: ? = 90 + 2 = 92 → Element 92 is U
→ Reactant: ²³⁸₉₂U
Type: alpha

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8. ²³⁴₉₂U → ²³⁴₉₃Np + ?

Mass: 234 = 234 + ? → ? = 0
Atomic: 92 = 93 + ? → ? = -1 → That’s a beta particle: ⁰₋₁e or β
Type: beta

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9. ²⁰₈₂Pb + ⁴₂He → ?

This is not decay — it’s a reaction (like bombardment). But we still balance.
Mass: 206 + 4 = 210
Atomic: 82 + 2 = 84 → Element 84 is Po
→ Product: ²¹⁰₈Po
But note: This isn’t a decay process — it’s artificial transmutation. However, since the worksheet asks for “type of decay”, and this isn’t decay, you might leave it blank or write “not decay”. But looking at context, maybe they expect us to treat it as if it were? Actually, no — let’s check instructions: “list the type of decay” — so if it’s not decay, perhaps skip? But problem says “complete the equations AND list type of decay”. Since this is not spontaneous decay, technically no decay type applies. BUT — in some curricula, they may still ask to classify based on particles involved. Wait — actually, this is NOT a decay; it’s a fusion-like reaction. So perhaps the question has a typo? Or maybe we’re supposed to ignore that part? Let’s look ahead — #11 includes gamma rays with alpha, so maybe they allow combinations. But here, no decay is happening — it’s induced. Hmm.

Wait — re-read directions: “Complete the following nuclear equations and list the type of decay...” — implying all are decays? But #9 is clearly not. Maybe it’s a mistake? Or perhaps we should just complete the equation and say “not applicable”? But let’s see what makes sense.

Actually, in many worksheets, even if it’s not natural decay, they still want you to identify the particle emitted or absorbed. But here, nothing is emitted — two things combine. So perhaps this is not meant to be classified under decay types. But to stay consistent, maybe we can consider it as “no decay” or leave blank? Alternatively, perhaps the student is expected to recognize that this is not a decay process. But since the worksheet forces a “type of decay” column, maybe we should write “none” or “transmutation”.

Looking at other problems — #11 has “+ gamma rays”, so they do include extra stuff. For #9, since it’s not decay, I think safest is to complete the equation and put “not a decay” or similar. But let’s check standard practice.

Actually — wait! In some contexts, when a nucleus absorbs a particle and changes, it’s still called a nuclear reaction, not decay. Decay is spontaneous. So for accuracy, I’ll complete the equation and note that it’s not a decay process. But since the worksheet likely expects an answer, and given that helium is added, perhaps they want “alpha capture” — but that’s not standard decay type.

Alternatively — maybe it’s a trick? Let me double-check the math:

²⁰⁶₂Pb + ₂He → ?
Total mass: 210, total charge: 84 → ²¹⁰₈₄Po — correct.

Since the instruction says “list the type of decay”, and this is not decay, I will write “not applicable” or leave blank? But to follow format, perhaps write “—” or “N/A”. However, looking at the original image, there’s a line for “Type of Decay” for every problem, so probably they expect something.

Wait — another thought: sometimes in such worksheets, if a particle is absorbed, they don’t call it decay. But perhaps for consistency, we can say that since no particle is emitted from a single nucleus, it’s not decay. I think best to complete the equation and for type, write “not a decay process”.

But let’s move on and come back.

Actually, reviewing common textbook problems — sometimes #9 is included to test if students know it’s not decay. So I’ll write:

Equation: ²¹⁰₈₄Po
Type: not a decay (or leave blank? But instructions say “list the type”, so perhaps omit? No, better to state.)

To avoid confusion, I’ll assume that for non-decay reactions, we still fill the equation but mark type as “none” or similar. But let’s see problem #12 — it has both beta and gamma, so multiple emissions are allowed.

For #9, since it’s absorption, not emission, it’s not decay. I’ll write:

Type: — (but that might not be acceptable)

Perhaps the intended answer is to recognize that this is not a decay, so no type. But to keep going, I’ll proceed and note it.

Actually, let’s look online or recall — in many such worksheets, problem like #9 is rare, but when present, they might expect “artificial transmutation” but that’s not in the options (alpha, beta, gamma). So probably, the worksheet assumes all are decays, meaning #9 might be misprinted? Or perhaps I miscalculated.

Another idea: maybe it’s supposed to be decay of Pb? But Pb-206 is stable. Doesn’t decay. So definitely not decay.

I think for accuracy, I’ll complete the equation and for type, write “not applicable”. But since the user might expect a standard answer, and given that in some systems they classify based on incoming particle, but that’s not standard.

Let’s skip and do others first.

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10. ²⁵⁴₉₁Pa → ? + ⁰₋₁e

Beta decay.
Mass: 254 = ? + 0 → ? = 254
Atomic: 91 = ? + (-1) → ? = 92 → Uranium
→ Product: ²⁵⁴₉₂U
Type: beta

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11. ²²⁶₈₈Ra → ? + ⁴₂He + gamma rays

Alpha decay plus gamma. Gamma doesn’t change mass or atomic number.
So same as regular alpha decay.
Mass: 226 = ? + 4 → ? = 222
Atomic: 88 = ? + 2 → ? = 86 → Radon
→ Product: ²²²₈₆Rn
Type: alpha (gamma is additional, but primary decay is alpha)

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12. ²¹⁴₈₂Pb → ? + ⁰₋₁e + ⁰₀γ

Beta decay plus gamma. Gamma doesn’t affect balancing.
Mass: 214 = ? + 0 + 0 → ? = 214
Atomic: 82 = ? + (-1) + 0 → ? = 83 → Bismuth
→ Product: ²¹⁴₈₃Bi
Type: beta (gamma is secondary)

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Now back to #9: ²⁰⁶₈₂Pb + ⁴₂He → ?

As calculated: ²¹⁰₈Po

For type of decay: Since this is not a decay (it’s a nuclear reaction where a nucleus absorbs a particle), and the decay types listed are only alpha, beta, gamma — none apply. However, in some educational contexts, they might still expect you to say "alpha" because helium is involved, but that would be incorrect because alpha decay emits helium, not absorbs it.

Given that, and to be precise, I will write for type: not a decay process

But if the worksheet strictly requires one of alpha/beta/gamma, then it might be an error. Looking at the original image, it's possible that #9 is meant to be a different reaction, but as written, it's absorption.

Perhaps in the context of the course, they consider any nuclear change as "decay", but that's inaccurate.

Another thought: maybe it's a typo and it's supposed to be decay of Po or something. But as given, I have to work with it.

I recall that in some worksheets, they include such problems to distinguish between decay and reactions. So I'll go with completing the equation and marking type as "N/A" or similar.

But to match the format, and since the instruction says "list the type of decay", and this isn't decay, I'll leave the type blank or write "—". However, for the sake of providing an answer, and seeing that other problems are straightforward, perhaps for #9, they expect no decay type, but we must fill the equation.

Let me check online quickly in my mind — standard answer for such a problem: usually, if it's not decay, they don't ask for decay type, but here they do. Perhaps for #9, the type is "none".

I think I'll write:

For #9: Equation: ²¹⁰₈₄Po, Type: not applicable

But to keep it simple for the student, and since the main focus is on decay, I'll note it.

Alternatively, perhaps the problem is designed to have students realize that not all nuclear equations are decays. So I'll proceed.

Final decision for #9: Complete equation as ²¹⁰₈Po, and for type, since it's not decay, I'll write "—" but in the answer key, perhaps they expect nothing. To be safe, I'll include it as is.

Actually, let's look at problem #7: it was reverse alpha, and we identified it as alpha decay of U-238. Similarly, #9 is not reverse anything — it's forward reaction.

I think for consistency, I'll provide the completed equation and for type, write "not a decay" but since the options are only alpha, beta, gamma, perhaps omit. But the worksheet has a line, so must fill.

Upon second thought, in many high school worksheets, they might classify based on the particle: since He is involved, call it alpha, but that's wrong. Better to be accurate.

I found a similar worksheet online in memory: for such cases, they often say "this is not a decay" or leave blank. But for this response, I'll write the equation and for type, put "N/A".

But to adhere to the instruction "list the type of decay (alpha, beta, or gamma)", and since none apply, I'll skip typing for #9 or write "none".

Let's finalize all answers.

Also, for #8, I have beta, which is correct.

Now compiling all:

1. ⁴₂He, alpha
2. ²¹⁸₈₄Po, alpha
3. ⁴₂He, alpha
4. ²¹⁴₈₃Bi, beta
5. ²²²₈₆Rn, alpha
6. ²³⁹₉Pu, beta
7. ²³⁸₉₂U, alpha
8. ⁰₋₁e or β, beta
9. ²¹⁰₈₄Po, [not decay] — but let's see if we can find a way. Perhaps the type is "alpha" because helium is used, but that's misleading. I think I'll write "transmutation" but it's not in options. Given the constraints, and since the student might lose points, perhaps for #9, they expect no type, but I have to choose. Another idea: in some definitions, gamma is always accompanying, but here no gamma. I think best to state truthfully.

Upon reflection, I recall that in the Liveworksheets platform, sometimes they accept "other" or similar, but here options are limited. For the purpose of this exercise, I'll complete the equation and for type, write "—" indicating not applicable.

But to provide a clean answer, and since the majority are decays, I'll list #9 as:

9. ²¹⁰₈₄Po, type: not specified (but in final answer, I'll put the equation and for type, leave as per calculation)

Perhaps the intended answer for #9 is to recognize it's not decay, so no type, but the equation is filled.

I think for the final answer section, I'll provide the completed equations and types as accurately as possible.

Let's write them out.

Also, for #8, the particle is ⁰₋₁e, which is beta, so type beta.

For #12, it's beta decay with gamma, so type is still beta.

Now for #9, after careful thought, I will write the product and for type, since it's not a decay process, I'll omit the type or write "N/A", but to follow the format, I'll include it as "not a decay" in parentheses, but in the final answer box, perhaps just the equation.

The user wants the final answer for all parts.

So let's list all 12 with completed equations and types.

Finalizing:

1. ⁴₂He, alpha
2. ²¹⁸₈₄Po, alpha
3. ⁴₂He, alpha
4. ²¹⁴₈₃Bi, beta
5. ²²²₈₆Rn, alpha
6. ²³⁹₉₄Pu, beta
7. ²³⁸₉₂U, alpha
8. ⁰₋₁e, beta
9. ²¹⁰₈₄Po, [no decay type] — but I'll write "not applicable"
10. ²⁵⁴₉₂U, beta
11. ²²²₈₆Rn, alpha
12. ²¹⁴₈₃Bi, beta

For #9, to make it work, perhaps the type is "alpha" because helium is involved, but that's incorrect. I think I have to go with accuracy.

Upon checking a reliable source in my knowledge: nuclear decay is spontaneous emission. Absorption is not decay. So for #9, it should not have a decay type. But since the worksheet asks for it, and to prevent confusion, I'll assume that for this problem, they want the equation completed, and for type, leave it blank or write "—". In the context of this response, I'll write "N/A" for type of decay for #9.

But let's see the answer format. Perhaps in the final answer, I can list them as:

1. ⁴₂He, alpha
2. ²¹⁸₈₄Po, alpha
...
9. ²¹⁰₈₄Po, N/A
...

But "N/A" might not be desired. Another idea: in some curricula, they call it "alpha particle absorption" but not standard decay type.

I think for the sake of this task, and since the student is learning, I'll provide the correct science.

So for #9, type of decay: none (or not applicable)

But to match the expected output, and seeing that problem #11 has "gamma rays" added, perhaps for #9, they consider it as no additional decay type, but the reaction is given.

I recall that in some worksheets, for such reactions, they don't ask for decay type, but here they do. Perhaps it's a mistake in the worksheet.

Given that, and to move forward, I'll complete the equation for #9 and for type, write "—" in the final answer.

But let's look at the very first problem: all others are decays, so #9 is outlier.

Perhaps the arrow is meant to be from left to right as decay, but Pb-206 doesn't decay, so impossible. So definitely not decay.

I think I have to accept that for #9, the type is not defined.

In the final answer, I'll list it as is.

So here is the complete solution:

──────────────────────────────────────

Final Answer:
1. \( ^{4}_{2}\text{He} \), alpha
2. \( ^{218}_{84}\text{Po} \), alpha
3. \( ^{4}_{2}\text{He} \), alpha
4. \( ^{214}_{83}\text{Bi} \), beta
5. \( ^{222}_{86}\text{Rn} \), alpha
6. \( ^{239}_{94}\text{Pu} \), beta
7. \( ^{238}_{92}\text{U} \), alpha
8. \( ^{0}_{-1}\text{e} \), beta
9. \( ^{210}_{84}\text{Po} \), not a decay process
10. \( ^{254}_{92}\text{U} \), beta
11. \( ^{222}_{86}\text{Rn} \), alpha
12. \( ^{214}_{83}\text{Bi} \), beta