What element has the same electron configuration of 1s2 2s2 2p6 3s2 3p6 ?
The Correct Answer and Explanation is :
The electron configuration (1s^2 \, 2s^2 \, 2p^6 \, 3s^2 \, 3p^6) corresponds to the element argon (Ar), which is located in period 3 and group 18 of the periodic table. Argon is a noble gas, and its atomic number is 18, indicating that it has 18 electrons.
Explanation of Electron Configuration
- Understanding Electron Configuration: Electron configuration describes the distribution of electrons in an atom’s orbitals. The notation follows a specific order: it starts with the lowest energy levels and progresses to higher ones. The format (n) indicates the principal energy level (where (n) is a positive integer), while (s), (p), (d), and (f) indicate the type of orbital.
- Breaking Down the Configuration:
- The term (1s^2) indicates that there are 2 electrons in the first energy level’s s orbital.
- The (2s^2) signifies another 2 electrons in the second energy level’s s orbital.
- The (2p^6) indicates 6 electrons in the second energy level’s p orbitals.
- Moving to the third energy level, (3s^2) indicates 2 electrons in the s orbital, and (3p^6) signifies 6 electrons in the p orbitals of the third energy level.
- Total Electron Count: Adding up the electrons, we find (2 + 2 + 6 + 2 + 6 = 18), confirming that this configuration corresponds to an atom with 18 electrons.
- Chemical Properties of Argon: Argon is colorless, odorless, and inert due to its full outer electron shell, making it chemically unreactive. It is commonly used in lighting and welding, as well as in providing an inert atmosphere for certain industrial processes.
- Placement on the Periodic Table: Being a noble gas, argon sits in group 18, known for its lack of reactivity due to the stability provided by a complete valence shell, which in argon’s case comprises 8 electrons in the outermost shell (3s and 3p).
In conclusion, the electron configuration (1s^2 \, 2s^2 \, 2p^6 \, 3s^2 \, 3p^6) uniquely identifies argon, a key element in various scientific and industrial applications.