Isotopes, Ions, and Atoms Worksheet for chemistry practice.

Let's solve this "Isotopes, Ions, and Atoms Worksheet" step by step.

We are given a list of atomic symbols with mass numbers and charges. We need to fill in:

- Atomic Number
- Mass Number
- Number of Protons
- Number of Electrons
- Number of Neutrons

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🔍 Key Concepts:

1. Atomic Number (Z) = Number of protons
→ This is the bottom number in the symbol (e.g., in $^{36}_{17}\text{Cl}$, atomic number = 17)

2. Mass Number (A) = Total number of protons + neutrons
→ This is the top number in the symbol

3. Number of Protons = Atomic Number

4. Number of Electrons =
- For neutral atoms: same as protons
- For ions:
- Add electrons for negative charge (anions)
- Subtract electrons for positive charge (cations)
→ Electrons = Protons − Charge (if charge is written as + or −)

5. Number of Neutrons = Mass Number − Atomic Number

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Now let’s go through each row one by one.

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1. $^{36}_{17}\text{Cl}$

- Symbol: Cl
- Charge: 0 (neutral atom)
- Atomic Number: 17
- Mass Number: 36
- Protons: 17
- Electrons: 17 (neutral)
- Neutrons: 36 − 17 = 19

✔ Row:
| Cl | 0 | 17 | 36 | 17 | 17 | 19 |

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2. $^{113}_{48}\text{Cd}^-$

- Charge: -1 (one extra electron)
- Atomic Number: 48
- Mass Number: 113
- Protons: 48
- Electrons: 48 + 1 = 49
- Neutrons: 113 − 48 = 65

✔ Row:
| Cd⁻ | -1 | 48 | 113 | 48 | 49 | 65 |

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3. $^{31}_{15}\text{P}^{3-}$

- Charge: -3
- Atomic Number: 15
- Mass Number: 31
- Protons: 15
- Electrons: 15 + 3 = 18
- Neutrons: 31 − 15 = 16

✔ Row:
| P³⁻ | -3 | 15 | 31 | 15 | 18 | 16 |

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4. $^{209}_{83}\text{Bi}^{3+}$

- Charge: +3
- Atomic Number: 83
- Mass Number: 209
- Protons: 83
- Electrons: 83 − 3 = 80
- Neutrons: 209 − 83 = 126

✔ Row:
| Bi³⁺ | +3 | 83 | 209 | 83 | 80 | 126 |

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5. $^{180}_{71}\text{Lu}$

- Neutral atom (no charge shown)
- Atomic Number: 71
- Mass Number: 180
- Protons: 71
- Electrons: 71
- Neutrons: 180 − 71 = 109

✔ Row:
| Lu | 0 | 71 | 180 | 71 | 71 | 109 |

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6. $^{128}_{53}\text{I}^-$

- Charge: -1
- Atomic Number: 53
- Mass Number: 128
- Protons: 53
- Electrons: 53 + 1 = 54
- Neutrons: 128 − 53 = 75

✔ Row:
| I⁻ | -1 | 53 | 128 | 53 | 54 | 75 |

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7. $^{128}_{40}\text{Zr}^{2+}$

- Charge: +2
- Atomic Number: 40
- Mass Number: 128
- Protons: 40
- Electrons: 40 − 2 = 38
- Neutrons: 128 − 40 = 88

✔ Row:
| Zr²⁺ | +2 | 40 | 128 | 40 | 38 | 88 |

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8. $^{188}_{76}\text{Os}^{4+}$

- Charge: +4
- Atomic Number: 76
- Mass Number: 188
- Protons: 76
- Electrons: 76 − 4 = 72
- Neutrons: 188 − 76 = 112

✔ Row:
| Os⁴⁺ | +4 | 76 | 188 | 76 | 72 | 112 |

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9. $^{238}_{92}\text{U}^{6+}$

- Charge: +6
- Atomic Number: 92
- Mass Number: 238
- Protons: 92
- Electrons: 92 − 6 = 86
- Neutrons: 238 − 92 = 146

✔ Row:
| U⁶⁺ | +6 | 92 | 238 | 92 | 86 | 146 |

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10. $^{116}_{49}\text{In}^{3+}$

- Charge: +3
- Atomic Number: 49
- Mass Number: 116
- Protons: 49
- Electrons: 49 − 3 = 46
- Neutrons: 116 − 49 = 67

✔ Row:
| In³⁺ | +3 | 49 | 116 | 49 | 46 | 67 |

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11. $^{206}_{82}\text{Pb}^{4+}$

- Charge: +4
- Atomic Number: 82
- Mass Number: 206
- Protons: 82
- Electrons: 82 − 4 = 78
- Neutrons: 206 − 82 = 124

✔ Row:
| Pb⁴⁺ | +4 | 82 | 206 | 82 | 78 | 124 |

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12. $^{79}_{34}\text{Se}^{2-}$

- Charge: -2
- Atomic Number: 34
- Mass Number: 79
- Protons: 34
- Electrons: 34 + 2 = 36
- Neutrons: 79 − 34 = 45

✔ Row:
| Se²⁻ | -2 | 34 | 79 | 34 | 36 | 45 |

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13. $^{42}_{21}\text{Sc}$

- Neutral atom
- Atomic Number: 21
- Mass Number: 42
- Protons: 21
- Electrons: 21
- Neutrons: 42 − 21 = 21

✔ Row:
| Sc | 0 | 21 | 42 | 21 | 21 | 21 |

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14. $^{108}_{47}\text{Ag}$

- Neutral atom
- Atomic Number: 47
- Mass Number: 108
- Protons: 47
- Electrons: 47
- Neutrons: 108 − 47 = 61

✔ Row:
| Ag | 0 | 47 | 108 | 47 | 47 | 61 |

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✔ Final Completed Table:

| Symbol | Charge | Atomic Number | Mass Number | Number of Protons | Number of Electrons | Number of Neutrons |
|-------------|--------|----------------|--------------|--------------------|----------------------|---------------------|
| $^{36}_{17}\text{Cl}$ | 0 | 17 | 36 | 17 | 17 | 19 |
| $^{113}_{48}\text{Cd}^-$ | -1 | 48 | 113 | 48 | 49 | 65 |
| $^{31}_{15}\text{P}^{3-}$ | -3 | 15 | 31 | 15 | 18 | 16 |
| $^{209}_{83}\text{Bi}^{3+}$ | +3 | 83 | 209 | 83 | 80 | 126 |
| $^{180}_{71}\text{Lu}$ | 0 | 71 | 180 | 71 | 71 | 109 |
| $^{128}_{53}\text{I}^-$ | -1 | 53 | 128 | 53 | 54 | 75 |
| $^{128}_{40}\text{Zr}^{2+}$ | +2 | 40 | 128 | 40 | 38 | 88 |
| $^{188}_{76}\text{Os}^{4+}$ | +4 | 76 | 188 | 76 | 72 | 112 |
| $^{238}_{92}\text{U}^{6+}$ | +6 | 92 | 238 | 92 | 86 | 146 |
| $^{116}_{49}\text{In}^{3+}$ | +3 | 49 | 116 | 49 | 46 | 67 |
| $^{206}_{82}\text{Pb}^{4+}$ | +4 | 82 | 206 | 82 | 78 | 124 |
| $^{79}_{34}\text{Se}^{2-}$ | -2 | 34 | 79 | 34 | 36 | 45 |
| $^{42}_{21}\text{Sc}$ | 0 | 21 | 42 | 21 | 21 | 21 |
| $^{108}_{47}\text{Ag}$ | 0 | 47 | 108 | 47 | 47 | 61 |

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📌 Summary Tips:

- Atomic number = number of protons.
- Mass number = protons + neutrons.
- Charge tells you how many electrons differ from protons:
- Positive charge → fewer electrons
- Negative charge → more electrons
- Neutrons = mass number − atomic number

Let me know if you'd like this as a downloadable table or image!