1s 2s 2p B. 1s 2s 2p C. 1s 2s 2p D. 1s 2s 2p

1s 2s 2p B. 1s 2s 2p C. 1s 2s 2p D. 1s 2s 2p

The Correct Answer and Explanation is:

The electron configuration describes how electrons are arranged in an atom, starting from the lowest energy level and moving to higher energy levels as needed. The sequence “1s 2s 2p” follows the Aufbau principle, which states that electrons fill atomic orbitals in order of increasing energy.

Here’s a breakdown of each part:

1. 1s: This is the first energy level, and the “s” orbital can hold a maximum of 2 electrons. The “1” refers to the first shell, and “s” is the type of orbital. It can hold up to 2 electrons.
2. 2s: The second energy level, which also contains an “s” orbital. It can hold up to 2 electrons.
3. 2p: The second energy level also contains “p” orbitals. The “p” orbitals can hold up to 6 electrons, but for this configuration, we are only showing part of the orbital that could be filled with up to 6 electrons.

For instance, the electron configuration of boron (B) would be 1s2 2s2 2p1, indicating that it has 5 electrons in total. This means the first energy level holds 2 electrons (1s), the second energy level holds 2 electrons in the s orbital (2s), and the remaining electron goes into one of the 2p orbitals.