Question

e. what is wrong with the following electron configurations: kr: 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁸ 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶5s²:

Explanation:

Step1: Analyze electron - configuration rules

Electron configurations follow the Aufbau principle, Pauli - exclusion principle, and Hund's rule. The maximum number of electrons in an s - orbital is 2, in a p - orbital is 6, and in a d - orbital is 10.

Step2: Examine the first configuration

The configuration [Kr]: 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁸ is incorrect because the p - subshell can hold a maximum of 6 electrons. In 4p⁸, there are 2 more electrons than the p - subshell capacity.

Step3: Examine the second configuration

The configuration 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶5s² is incorrect for the element represented. After filling 4p⁶, the next electrons should go into the 5p orbital instead of jumping to 6s². The correct order of filling after 4p⁶ is 5s, then 4d, then 5p.

Answer:

In the first configuration, 4p⁸ has more electrons than the p - subshell capacity. In the second configuration, the electron - filling order is incorrect as it skips the 5p and 4d orbitals and goes directly to 6s².