Multiple Choice
How many electrons can the first electron shell (n = 1) hold?
2
views
10. Periodic Properties of the Elements
The Electron Configuration
Struggling with General Chemistry?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
Which of the following electron configurations is possible for a nitrogen atom in an excited state?
A
1s^2 2s^2 2p^4
B
1s^2 2s^2 2p^3
C
1s^2 2s^1 2p^4
D
1s^2 2s^2 2p^2 3s^1
Verified step by step guidance1
Recall that the ground state electron configuration of a nitrogen atom (atomic number 7) is $1s^2 2s^2 2p^3$, meaning it has 7 electrons distributed in the lowest energy orbitals following the Aufbau principle.
Understand that an excited state occurs when one or more electrons absorb energy and move to a higher energy orbital, resulting in a configuration different from the ground state but still obeying the Pauli exclusion principle and Hund's rule.
Check each given configuration to see if the total number of electrons equals 7, since nitrogen has 7 electrons, and verify if the distribution is possible by moving electrons from lower to higher orbitals without violating electron capacity rules.
For example, the configuration $1s^2 2s^1 2p^4$ shows one electron promoted from the $2s$ orbital to the $2p$ orbital, which is a valid excited state because it maintains the total electron count and respects orbital capacities.
Conclude that configurations like $1s^2 2s^2 2p^4$ (which has 8 electrons) or $1s^2 2s^2 2p^2 3s^1$ (which also sums to 8 electrons) are not possible for nitrogen, while $1s^2 2s^1 2p^4$ is a valid excited state configuration.
Related Videos
Related Practice
The Electron Configuration practice set
Problem sets built by lead tutorsExpert video explanations