Fill in the blanks for protons, neutrons, electrons, atomic mass, and atomic number for each element.

Let's solve this step by step. We are given a table with various elements and some of their properties (protons, neutrons, electrons, atomic mass, atomic number). We need to fill in the blanks using the following key principles:

Key Concepts:

1. Atomic Number (Z) = Number of protons = Number of electrons (in neutral atoms)
2. Atomic Mass (A) ≈ Protons + Neutrons
3. Neutrons = Atomic Mass – Protons
4. For neutral atoms: Electrons = Protons

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We'll go row by row.

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Row 1: He (Helium)

- Given: Neutrons = 2
- Helium has atomic number = 2 → So protons = 2
- Electrons = protons = 2 (neutral atom)
- Atomic mass = protons + neutrons = 2 + 2 = 4 amu
- Atomic number = 2

✔ Answer:
Protons: 2, Electrons: 2, Atomic Mass: 4, Atomic Number: 2

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Row 2: N (Nitrogen)

- Given: Atomic mass = 15
- Nitrogen has atomic number = 7 → so protons = 7
- Electrons = 7 (neutral)
- Neutrons = Atomic mass – protons = 15 – 7 = 8

✔ Answer:
Protons: 7, Neutrons: 8, Electrons: 7, Atomic Number: 7

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Row 3: Unknown element

- Protons = 23
- Neutrons = 29
- Atomic mass = protons + neutrons = 23 + 29 = 52
- Electrons = protons = 23 (neutral)
- Atomic number = 23 → Element is Vanadium (V)

✔ Answer:
Element: V, Electrons: 23, Atomic Mass: 52, Atomic Number: 23

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Row 4: Unknown element

- Electrons = 30
- Since neutral, protons = 30
- Atomic number = 30 → Zinc (Zn)
- Atomic mass = 64 (given)
- Neutrons = 64 – 30 = 34

✔ Answer:
Element: Zn, Protons: 30, Neutrons: 34, Atomic Number: 30

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Row 5: Unknown element

- Atomic mass = 99
- Atomic number = 43 → Technetium (Tc)
- Protons = 43
- Electrons = 43 (neutral)
- Neutrons = 99 – 43 = 56

✔ Answer:
Element: Tc, Protons: 43, Neutrons: 56, Electrons: 43

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Row 6: Lu (Lutetium)

- Given: Atomic mass = 176
- Lutetium has atomic number = 71 → protons = 71
- Electrons = 71 (neutral)
- Neutrons = 176 – 71 = 105

✔ Answer:
Protons: 71, Neutrons: 105, Electrons: 71, Atomic Number: 71

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Row 7: Unknown element

- Protons = 87
- Atomic mass = 224
- Atomic number = 87 → Francium (Fr)
- Electrons = 87
- Neutrons = 224 – 87 = 137

✔ Answer:
Element: Fr, Neutrons: 137, Electrons: 87, Atomic Number: 87

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Row 8: Unknown element

- Neutrons = 157
- Atomic number = 101 → Mendelevium (Md)
- Protons = 101
- Electrons = 101
- Atomic mass = protons + neutrons = 101 + 157 = 258

✔ Answer:
Element: Md, Protons: 101, Electrons: 101, Atomic Mass: 258

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Row 9: Gd (Gadolinium)

- Atomic mass = 155
- Gadolinium has atomic number = 64 → protons = 64
- Electrons = 64
- Neutrons = 155 – 64 = 91

✔ Answer:
Protons: 64, Neutrons: 91, Electrons: 64, Atomic Number: 64

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Row 10: Unknown element

- Neutrons = 157
- Electrons = 102
- Since neutral, protons = 102
- Atomic number = 102 → Nobelium (No)
- Atomic mass = protons + neutrons = 102 + 157 = 259

✔ Answer:
Element: No, Protons: 102, Atomic Mass: 259, Atomic Number: 102

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Row 11: Sm (Samarium)

- Neutrons = 88
- Samarium has atomic number = 62 → protons = 62
- Electrons = 62
- Atomic mass = 62 + 88 = 150

✔ Answer:
Protons: 62, Electrons: 62, Atomic Mass: 150, Atomic Number: 62

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Final Completed Table:

| Element | Protons | Neutrons | Electrons | Atomic Mass (amu) | Atomic Number |
|--------|--------|---------|----------|------------------|---------------|
| He | 2 | 2 | 2 | 4 | 2 |
| N | 7 | 8 | 7 | 15 | 7 |
| V | 23 | 29 | 23 | 52 | 23 |
| Zn | 30 | 34 | 30 | 64 | 30 |
| Tc | 43 | 56 | 43 | 99 | 43 |
| Lu | 71 | 105 | 71 | 176 | 71 |
| Fr | 87 | 137 | 87 | 224 | 87 |
| Md | 101 | 157 | 101 | 258 | 101 |
| Gd | 64 | 91 | 64 | 155 | 64 |
| No | 102 | 157 | 102 | 259 | 102 |
| Sm | 62 | 88 | 62 | 150 | 62 |

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✔ All blanks filled! Let me know if you'd like this as a downloadable table or explanation for any specific row.