Q54E - Chemistry (OpenStax)

Question

Question: Using complete subshell notation (1s²2s²2p⁶, and so forth), predict the electron configurations of the following

ions.

(a) N^3–

(b) Ca²⁺

(c) S^–

(d) Cs²⁺

(e) Cr²⁺

(f) Gd³⁺

Step-by-Step Solution

Answer

1. N^3- = 1s²2s²2p⁶
2. Ca²⁺ = 1s²2s²2p⁶3s²3p⁶
3. S^2- = 1s²2s²2p⁶3s²3p⁶
4. Cs²⁺ = 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶4d¹⁰
5. Cr²⁺ = 1s²2s²2p⁶3s²3p⁶3d⁴
6. Gd³⁺ = 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶4d¹⁰5s²5p⁶4f⁷

Step 1: predicting the electron configuration of N 3-

Observing the periodic table, we can write the electron configuration of N^3-

The electron configuration for N^3- is 1s²2s²2p⁶.

Step 2: predicting the electron configuration of Ca 2+

Observing the periodic table, we can write the electron configuration of Ca²⁺

The electron configuration for Ca²⁺ is 1s²2s²2p⁶3s²3p⁶

Step 3: predicting the electron configuration of S 2-

Observing the periodic table, we can write the electron configuration of S^2-

The electron configuration for S^2- is 1s²2s²2p⁶3s²3p⁶

Step 4: predicting the electron configuration of Cs 2+

Observing the periodic table, we can write the electron configuration of Cs²⁺

The electron configuration for Cs²⁺ is 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶4d¹⁰

Step 5: predicting the electron configuration of Cr 2+

Observing the periodic table, we can write the electron configuration of Cr²⁺

The electron configuration for Cr²⁺ is 1s²2s²2p⁶3s²3p⁶3d⁴

Step 6: predicting the electron configuration of Gd 3+

Observing the periodic table, we can write the electron configuration of Gd³⁺ 

The electron configuration for Gd³⁺ is 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶4d¹⁰5s²5p⁶4f⁷