Solved Electron Configuration and Orbital Diagram Worksheet ... - Free Printable

Here's the completed Electron Configuration and Orbital Diagram Worksheet, with explanations for each entry.

---

📌 Key Concepts:

- Total Electrons = Atomic number (for neutral atoms) or adjusted for ions.
- Core Electrons = All electrons except valence electrons. Usually inner-shell electrons (e.g., for 2nd period, core = 1s²).
- Valence Electrons = Electrons in the outermost shell (highest n value). For main group elements, this is the group number (for groups 1–2, 13–18).
- Electron Configuration: Follows Aufbau principle, Pauli exclusion, and Hund’s rule.
- Orbital Diagram: Boxes represent orbitals; arrows represent electrons (↑↓ = paired, ↑ = unpaired).

---

## ✔ Completed Table:

| Element | Total Electrons | Core Electrons | Valence Electrons | Electron Configuration | Orbital Diagram (Simplified - showing valence only) |
|---------|------------------|----------------|-------------------|----------------------------------|------------------------------------------------------|
| C | 6 | 2 | 4 | 1s² 2s² 2p² | 2s: [↑↓] 2p: [↑] [↑] [ ] |
| N | 7 | 2 | 5 | 1s² 2s² 2p³ | 2s: [↑↓] 2p: [↑] [↑] [↑] |
| O | 8 | 2 | 6 | 1s² 2s² 2p⁴ | 2s: [↑↓] 2p: [↑↓] [↑] [↑] |
| O²⁻ | 10 | 2 | 8 | 1s² 2s² 2p⁶ | 2s: [↑↓] 2p: [↑↓] [↑↓] [↑↓] |
| F | 9 | 2 | 7 | 1s² 2s² 2p⁵ | 2s: [↑↓] 2p: [↑↓] [↑↓] [↑] |
| F⁻ | 10 | 2 | 8 | 1s² 2s² 2p⁶ | 2s: [↑↓] 2p: [↑↓] [↑↓] [↑↓] |
| Mg | 12 | 10 | 2 | 1s² 2s² 2p⁶ 3s² | 3s: [↑↓] |
| Mg⁺ | 11 | 10 | 1 | 1s² 2s² 2p⁶ 3s¹ | 3s: [↑] |
| Mg²⁺ | 10 | 10 | 0 | 1s² 2s² 2p⁶ | (No valence electrons — same as Ne) |
| Sn | 50 | 46 | 4 | [Kr] 5s² 4d¹⁰ 5p² | 5s: [↑↓] 5p: [↑] [↑] [ ] |
| Sn²⁺ | 48 | 46 | 2 | [Kr] 5s² 4d¹⁰ | 5s: [↑↓] |
| Sn⁴⁺ | 46 | 46 | 0 | [Kr] 4d¹⁰ | (No valence electrons — 5s and 5p emptied) |

---

## 🔍 Detailed Explanations:

---

N (Nitrogen)

- Atomic number = 7 → 7 total electrons
- Core = 1s² = 2 electrons
- Valence = 2s²2p³ = 5 electrons
- Config: 1s² 2s² 2p³
- Orbital diagram: 2s full, 2p has 3 unpaired electrons (Hund’s Rule)

---

O (Oxygen)

- Atomic number = 8 → 8 total electrons
- Core = 2, Valence = 6
- Config: 1s² 2s² 2p⁴
- Orbital diagram: 2p has one paired orbital and two unpaired (↑↓ ↑ ↑)

---

O²⁻ (Oxide Ion)

- Gains 2 electrons → 8 + 2 = 10 electrons
- Core = 2, Valence = 8 (full octet)
- Config: 1s² 2s² 2p⁶ → same as Neon
- Orbital diagram: All 2p orbitals filled

---

F (Fluorine)

- Atomic number = 9 → 9 electrons
- Core = 2, Valence = 7
- Config: 1s² 2s² 2p⁵
- Orbital diagram: 2p has one unpaired electron

---

F⁻ (Fluoride Ion)

- Gains 1 electron → 10 electrons
- Core = 2, Valence = 8
- Config: 1s² 2s² 2p⁶ → same as Ne
- Orbital diagram: All 2p orbitals filled

---

Mg (Magnesium)

- Atomic number = 12 → 12 electrons
- Core = 1s²2s²2p⁶ = 10 electrons (Ne core)
- Valence = 3s² = 2 electrons
- Config: 1s² 2s² 2p⁶ 3s²
- Orbital diagram: 3s orbital filled

---

Mg⁺ (Magnesium ion, +1 charge)

- Loses 1 electron → 11 electrons
- Core = 10, Valence = 1 (3s¹)
- Config: 1s² 2s² 2p⁶ 3s¹
- Orbital diagram: 3s has one unpaired electron

---

Mg²⁺ (Magnesium ion, +2 charge)

- Loses 2 electrons → 10 electrons
- Core = 10, Valence = 0
- Config: 1s² 2s² 2p⁶ → same as Ne
- Orbital diagram: No valence electrons shown (core only)

---

Sn (Tin)

- Atomic number = 50 → 50 electrons
- Core = [Kr] + 4d¹⁰ = 36 + 10 = 46 electrons? Actually, let’s clarify:

> Important Note on Core Electrons for Sn:
> - Sn is in period 5, group 14.
> - Full config: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p²
> - Noble gas core = [Kr] (36 electrons)
> - But “core” typically means all non-valence electrons. Valence electrons are in 5s and 5p → 4 valence electrons.
> - So core = 50 – 4 = 46 electrons

✔ Confirmed.

- Config: [Kr] 5s² 4d¹⁰ 5p²
- Orbital diagram: 5s full, 5p has 2 unpaired electrons (in separate orbitals per Hund’s rule)

---

Sn²⁺ (Tin(II) ion)

- Loses 2 electrons → 48 electrons
- Typically loses 5p electrons first → so 5s² remains
- Config: [Kr] 5s² 4d¹⁰
- Core = 46 (same as Sn), Valence = 2 (only 5s² now)
- Orbital diagram: 5s orbital filled

---

Sn⁴⁺ (Tin(IV) ion)

- Loses 4 electrons → 46 electrons
- Loses both 5s and 5p electrons → leaves [Kr] 4d¹⁰
- Core = 46 (all electrons are now core — no valence shell)
- Valence = 0
- Orbital diagram: No valence orbitals shown (since 5s/5p empty)

---

## 🧠 Summary Tips:

- For ions, adjust total electrons: add for anions, subtract for cations.
- Core electrons = total electrons minus valence electrons.
- Valence electrons for main group = group number (for groups 1–2, 13–18).
- For transition metals like Sn, valence includes ns and np (sometimes nd too, but for Sn²⁺/Sn⁴⁺, we consider s/p electrons lost first).

---

Let me know if you’d like the orbital diagrams drawn out visually or need help with noble gas shorthand notation!