isotope notation worksheet FREE - The Animated Teacher - Free Printable

Let's solve the isotope notation problems step by step, based on the worksheet shown in the image.

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🔹 Understanding Isotope Notation

Isotope notation is written as:

\[
^{\text{Mass Number}}_{\text{Atomic Number}}\text{Element}
\]

Where:
- Mass number = protons + neutrons
- Atomic number = number of protons (defines the element)
- The element symbol is used from the periodic table.

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## ✔ Part 1: Write the correct isotopic notation

We are given proton and neutron counts. We need to find:
- Mass number = protons + neutrons
- Atomic number = number of protons → this tells us the element
- Then write the isotope notation.

Let’s go through each one.

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1. 26 protons, 26 neutrons

- Protons = 26 → Element is Iron (Fe)
- Mass number = 26 + 26 = 52
→ \(\boxed{^{52}_{26}\text{Fe}}\)

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2. 92 protons, 146 neutrons

- Protons = 92 → Element is Uranium (U)
- Mass number = 92 + 146 = 238
→ \(\boxed{^{238}_{92}\text{U}}\)

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3. 7 protons, 8 neutrons

- Protons = 7 → Element is Nitrogen (N)
- Mass number = 7 + 8 = 15
→ \(\boxed{^{15}_{7}\text{N}}\)

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4. 8 protons, 10 neutrons

- Protons = 8 → Element is Oxygen (O)
- Mass number = 8 + 10 = 18
→ \(\boxed{^{18}_{8}\text{O}}\)

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5. 66 protons, 92 neutrons

- Protons = 66 → Element is Dysprosium (Dy)
- Mass number = 66 + 92 = 158
→ \(\boxed{^{158}_{66}\text{Dy}}\)

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6. 17 protons, 20 neutrons

- Protons = 17 → Element is Chlorine (Cl)
- Mass number = 17 + 20 = 37
→ \(\boxed{^{37}_{17}\text{Cl}}\)

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7. 18 protons, 22 neutrons

- Protons = 18 → Element is Argon (Ar)
- Mass number = 18 + 22 = 40
→ \(\boxed{^{40}_{18}\text{Ar}}\)

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8. 82 protons, 125 neutrons

- Protons = 82 → Element is Lead (Pb)
- Mass number = 82 + 125 = 207
→ \(\boxed{^{207}_{82}\text{Pb}}\)

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## ✔ Part 2: Determine the number of protons and neutrons

Given isotope notation, find p (protons) and n (neutrons).

Recall:
- Protons = atomic number (subscript)
- Neutrons = mass number – protons

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1. \(^{146}_{60}\text{Nd}\)

- p = 60
- n = 146 – 60 = 86
→ p: 60, n: 86

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2. \(^{126}_{52}\text{Te}\)

- p = 52
- n = 126 – 52 = 74
→ p: 52, n: 74

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3. \(^{107}_{47}\text{Ag}\)

- p = 47
- n = 107 – 47 = 60
→ p: 47, n: 60

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4. \(^{195}_{78}\text{Pt}\)

- p = 78
- n = 195 – 78 = 117
→ p: 78, n: 117

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5. \(^{119}_{50}\text{Sn}\)

- p = 50
- n = 119 – 50 = 69
→ p: 50, n: 69

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## ✔ Part 3: Record the isotope notation for the following isotopes

Now we're given names like "Calcium-40" — meaning mass number is 40, and element is Calcium.

We need to find atomic number from periodic table.

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1. Calcium-40

- Ca has atomic number 20
→ \(\boxed{^{40}_{20}\text{Ca}}\)

2. Calcium-42

→ \(\boxed{^{42}_{20}\text{Ca}}\)

3. Calcium-43

→ \(\boxed{^{43}_{20}\text{Ca}}\)

4. Calcium-44

→ \(\boxed{^{44}_{20}\text{Ca}}\)

5. Calcium-46

→ \(\boxed{^{46}_{20}\text{Ca}}\)

6. Calcium-48

→ \(\boxed{^{48}_{20}\text{Ca}}\)

7. Iron-54

- Fe has atomic number 26
→ \(\boxed{^{54}_{26}\text{Fe}}\)

8. Iron-56

→ \(\boxed{^{56}_{26}\text{Fe}}\)

9. Iron-57

→ \(\boxed{^{57}_{26}\text{Fe}}\)

10. Iron-58

→ \(\boxed{^{58}_{26}\text{Fe}}\)

11. Oxygen-16

- O has atomic number 8
→ \(\boxed{^{16}_{8}\text{O}}\)

12. Oxygen-17

→ \(\boxed{^{17}_{8}\text{O}}\)

13. Oxygen-18

→ \(\boxed{^{18}_{8}\text{O}}\)

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## ✔ Summary of Key Concepts

| Term | Meaning |
|------|--------|
| Atomic Number | Number of protons (defines the element) |
| Mass Number | Protons + Neutrons |
| Isotope Notation | \({}^{A}_{Z}\text{X}\), where A = mass number, Z = atomic number, X = element symbol |

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🟩 Final Answer Sheet (All Answers)

#### Part 1: Isotopic Notation
1. \(^{52}_{26}\text{Fe}\)
2. \(^{238}_{92}\text{U}\)
3. \(^{15}_{7}\text{N}\)
4. \(^{18}_{8}\text{O}\)
5. \(^{158}_{66}\text{Dy}\)
6. \(^{37}_{17}\text{Cl}\)
7. \(^{40}_{18}\text{Ar}\)
8. \(^{207}_{82}\text{Pb}\)

#### Part 2: Protons and Neutrons
1. Nd: p=60, n=86
2. Te: p=52, n=74
3. Ag: p=47, n=60
4. Pt: p=78, n=117
5. Sn: p=50, n=69

#### Part 3: Isotope Notation from Names
1. \(^{40}_{20}\text{Ca}\)
2. \(^{42}_{20}\text{Ca}\)
3. \(^{43}_{20}\text{Ca}\)
4. \(^{44}_{20}\text{Ca}\)
5. \(^{46}_{20}\text{Ca}\)
6. \(^{48}_{20}\text{Ca}\)
7. \(^{54}_{26}\text{Fe}\)
8. \(^{56}_{26}\text{Fe}\)
9. \(^{57}_{26}\text{Fe}\)
10. \(^{58}_{26}\text{Fe}\)
11. \(^{16}_{8}\text{O}\)
12. \(^{17}_{8}\text{O}\)
13. \(^{18}_{8}\text{O}\)

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Let me know if you'd like a printable version or explanation of how to use the periodic table!