Question

write the complete full electron configurations(e.g. 1s²2s²2p⁵) and abbreviated (noble gas notation) configuration for the following: # of e⁻ element (atom) full e⁻ configuration abbreviated (noble gas) e⁻ configuration 1) lithium 2) sulfur 3) calcium 4) nitrogen 5) magnesium write the abbreviated (noble gas notation) ground state electron configurations and circle the valence shell electrons for the following: # of electrons element 6) hydrogen 7) phosphorus 8) bromine 9) cobalt 10) zinc write the full electron configuration and noble gas notation electron configurations for the following atoms and ions: element / ions atomic number # of e⁻ electron configuration cl cl¹⁻ al al⁺³

Explanation:

Step1: Recall atomic numbers for electrons count

The atomic number is equal to the number of electrons in a neutral atom. For ions, adjust the electron - count based on the charge.

Step2: Write full electron configurations

Use the Aufbau principle (fill orbitals in order of increasing energy: 1s < 2s < 2p < 3s < 3p < 4s < 3d < 4p < 5s < 4d < 5p < 6s < 4f < 5d < 6p < 7s < 5f < 6d < 7p).

Step3: Write abbreviated (noble - gas) configurations

Find the nearest noble gas with a lower atomic number and use its symbol in brackets, then write the remaining electron configuration.

Answer:

1)

• # of e⁻: 3
• full e⁻ configuration: $1s^{2}2s^{1}$
• abbreviated (noble gas) e⁻ configuration: $[He]2s^{1}$

2)

• # of e⁻: 16
• full e⁻ configuration: $1s^{2}2s^{2}2p^{6}3s^{2}3p^{4}$
• abbreviated (noble gas) e⁻ configuration: $[Ne]3s^{2}3p^{4}$

3)

• # of e⁻: 20
• full e⁻ configuration: $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}$
• abbreviated (noble gas) e⁻ configuration: $[Ar]4s^{2}$

4)

• # of e⁻: 7
• full e⁻ configuration: $1s^{2}2s^{2}2p^{3}$
• abbreviated (noble gas) e⁻ configuration: $[He]2s^{2}2p^{3}$

5)

• # of e⁻: 12
• full e⁻ configuration: $1s^{2}2s^{2}2p^{6}3s^{2}$
• abbreviated (noble gas) e⁻ configuration: $[Ne]3s^{2}$

6)

• # of e⁻: 1
• abbreviated (noble gas) e⁻ configuration: $[H]1s^{1}$ (since there is no smaller noble - gas, we can write it like this, or just $1s^{1}$)
• Valence shell electron: $1s^{1}$ (circle $1s^{1}$)

7)

• # of e⁻: 15
• abbreviated (noble gas) e⁻ configuration: $[Ne]3s^{2}3p^{3}$
• Valence shell electrons: $3s^{2}3p^{3}$ (circle $3s^{2}3p^{3}$)

8)

• # of e⁻: 35
• abbreviated (noble gas) e⁻ configuration: $[Ar]4s^{2}3d^{10}4p^{5}$
• Valence shell electrons: $4s^{2}4p^{5}$ (circle $4s^{2}4p^{5}$)

9)

• # of e⁻: 27
• abbreviated (noble gas) e⁻ configuration: $[Ar]4s^{2}3d^{7}$
• Valence shell electrons: $4s^{2}3d^{7}$ (circle $4s^{2}3d^{7}$)

10)

• # of e⁻: 30
• abbreviated (noble gas) e⁻ configuration: $[Ar]4s^{2}3d^{10}$
• Valence shell electrons: $4s^{2}3d^{10}$ (circle $4s^{2}3d^{10}$)

For the table:

• Cl:
• Atomic number: 17
• # of e⁻: 17
• full electron configuration: $1s^{2}2s^{2}2p^{6}3s^{2}3p^{5}$
• noble - gas notation: $[Ne]3s^{2}3p^{5}$
• Cl⁻:
• Atomic number: 17
• # of e⁻: 18
• full electron configuration: $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}$
• noble - gas notation: $[Ar]$
• Al:
• Atomic number: 13
• # of e⁻: 13
• full electron configuration: $1s^{2}2s^{2}2p^{6}3s^{2}3p^{1}$
• noble - gas notation: $[Ne]3s^{2}3p^{1}$
• Al³⁺:
• Atomic number: 13
• # of e⁻: 10
• full electron configuration: $1s^{2}2s^{2}2p^{6}$
• noble - gas notation: $[Ne]$