Question

practice: electron configurations
part 1: write out the electron configurations for the following atoms.

1. be:
2. f:
3. p:
4. cu:
5. hg:

part 2: write out the electron configurations in noble gas notation for the following atoms.

1. b:
2. ca:
3. cl:
4. mn:
5. pb:

13: in concept 1 we learned how to draw lewis structures. now go back and draw the lewis structure for each element above except the transition metals.

Explanation:

Step1: Find Be's atomic number (4)

Fill orbitals by Aufbau principle: $1s^2 2s^2$

Step2: Find F's atomic number (9)

Fill orbitals by Aufbau principle: $1s^2 2s^2 2p^5$

Step3: Find P's atomic number (15)

Fill orbitals by Aufbau principle: $1s^2 2s^2 2p^6 3s^2 3p^3$

Step4: Find Cu's atomic number (29)

Use stable full d-orbital exception: $1s^2 2s^2 2p^6 3s^2 3p^6 3d^{10} 4s^1$

Step5: Find Hg's atomic number (80)

Use stable full f/d-orbitals: $1s^2 2s^2 2p^6 3s^2 3p^6 3d^{10} 4s^2 4p^6 4d^{10} 5s^2 5p^6 4f^{14} 5d^{10} 6s^2$

Step6: Find B's noble gas core (He, Z=2)

Add valence electrons: $[He] 2s^2 2p^1$

Step7: Find Ca's noble gas core (Ar, Z=18)

Add valence electrons: $[Ar] 4s^2$

Step8: Find Cl's noble gas core (Ne, Z=10)

Add valence electrons: $[Ne] 3s^2 3p^5$

Step9: Find Mn's noble gas core (Ar, Z=18)

Add valence electrons: $[Ar] 3d^5 4s^2$

Step10: Find Pb's noble gas core (Xe, Z=54)

Add valence electrons: $[Xe] 4f^{14} 5d^{10} 6s^2 6p^2$

Step11: Identify non-transition elements

List: Be, F, P, B, Ca, Cl, Pb

Step12: Draw Lewis structures for each

Show valence electrons as dots around element symbol.

Answer:

Part 1:

1. Be: $1s^2 2s^2$
2. F: $1s^2 2s^2 2p^5$
3. P: $1s^2 2s^2 2p^6 3s^2 3p^3$
4. Cu: $1s^2 2s^2 2p^6 3s^2 3p^6 3d^{10} 4s^1$
5. Hg: $1s^2 2s^2 2p^6 3s^2 3p^6 3d^{10} 4s^2 4p^6 4d^{10} 5s^2 5p^6 4f^{14} 5d^{10} 6s^2$

Part 2:

1. B: $[He] 2s^2 2p^1$
2. Ca: $[Ar] 4s^2$
3. Cl: $[Ne] 3s^2 3p^5$
4. Mn: $[Ar] 3d^5 4s^2$
5. Pb: $[Xe] 4f^{14} 5d^{10} 6s^2 6p^2$

Part 3 (Lewis Structures):

• Be: $\cdot Be \cdot$ (2 valence electrons)
• F:

$$\begin{array}{l}\cdot \\\ :\ddot{F}: \\\ \cdot\end{array}$$

(7 valence electrons)

• P:

$$\begin{array}{l}\cdot \\\ :\dot{P}: \\\ \cdot \end{array}$$

(5 valence electrons)

• B: $\cdot \dot{B} \cdot$ (3 valence electrons)
• Ca: $\cdot Ca \cdot$ (2 valence electrons)
• Cl:

$$\begin{array}{l}\cdot \\\ :\ddot{Cl}: \\\ \cdot\end{array}$$

(7 valence electrons)

• Pb:

$$\begin{array}{l}\cdot \\\ :\dot{Pb}: \\\ \cdot \end{array}$$

(4 valence electrons)