Question

For each element, indicate the number of valence electrons, core electrons, and unpaired electrons in the ground state: (a) nitrogen, (b) silicon, (c) chlorine.

Short answer

(a) Nitrogen: 5 valence electrons, 2 core electrons, and 3 unpaired electrons. (b) Silicon: 4 valence electrons, 10 core electrons, and 2 unpaired electrons. (c) Chlorine: 7 valence electrons, 10 core electrons, and 1 unpaired electron.

Step-by-step solution

(a) Nitrogen

: 1. Determine the atomic number: Nitrogen has an atomic number of 7. 2. Write the electron configuration: For Nitrogen, the electron configuration is 1s² 2s² 2p³. 3. Analyze the electron configuration: - Valence electrons: There are 5 valence electrons in Nitrogen (2 from the 2s orbital and 3 from the 2p orbital). - Core electrons: There are 2 core electrons in Nitrogen (from the 1s orbital). - Unpaired electrons: There are 3 unpaired electrons in Nitrogen (from the 2p orbital).

(b) Silicon

: 1. Determine the atomic number: Silicon has an atomic number of 14. 2. Write the electron configuration: For Silicon, the electron configuration is 1s² 2s² 2p6 3s² 3p². 3. Analyze the electron configuration: - Valence electrons: There are 4 valence electrons in Silicon (2 from the 3s orbital and 2 from the 3p orbital). - Core electrons: There are 10 core electrons in Silicon (2 from the 1s orbital, 2 from the 2s orbital, and 6 from the 2p orbital). - Unpaired electrons: There are 2 unpaired electrons in Silicon (from the 3p orbital).

(c) Chlorine

: 1. Determine the atomic number: Chlorine has an atomic number of 17. 2. Write the electron configuration: For Chlorine, the electron configuration is 1s² 2s² 2p6 3s² 3p5. 3. Analyze the electron configuration: - Valence electrons: There are 7 valence electrons in Chlorine (2 from the 3s orbital and 5 from the 3p orbital). - Core electrons: There are 10 core electrons in Chlorine (2 from the 1s orbital, 2 from the 2s orbital, and 6 from the 2p orbital). - Unpaired electrons: There is 1 unpaired electron in Chlorine (from the 3p orbital).