What will be the maximum number of electrons in the M-shell (orbit)?

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Points to Remember:

  • Electron shells and subshells
  • Quantum numbers and their significance
  • Maximum electron capacity of shells

Introduction:

The question pertains to the maximum number of electrons that can occupy the M-shell (or third principal energy level) of an atom. Understanding this requires knowledge of atomic structure and the principles governing electron configuration. Electrons in an atom are arranged in shells (also called energy levels) and subshells, each capable of holding a specific maximum number of electrons. The M-shell is the third shell from the nucleus. The distribution of electrons is governed by quantum numbers, which define the properties of atomic orbitals.

Body:

1. Quantum Numbers and Electron Capacity:

The maximum number of electrons a shell can hold is determined by the principal quantum number (n). The M-shell corresponds to n=3. The number of subshells within a shell is equal to n. Therefore, the M-shell (n=3) has three subshells: s, p, and d.

  • s-subshell: Can hold a maximum of 2 electrons.
  • p-subshell: Can hold a maximum of 6 electrons (3 orbitals, each holding 2 electrons).
  • d-subshell: Can hold a maximum of 10 electrons (5 orbitals, each holding 2 electrons).

2. Calculating Maximum Electrons in the M-shell:

To find the total maximum number of electrons in the M-shell, we sum the capacities of its subshells:

2 (s-subshell) + 6 (p-subshell) + 10 (d-subshell) = 18 electrons

3. Illustrative Example:

Consider the element Argon (Ar). Its atomic number is 18, meaning it has 18 electrons. The electron configuration of Argon is 1s²2s²2p⁶3s²3p⁶. Notice that all the electrons in the M-shell (3s and 3p subshells) are filled, totaling 8 electrons. However, the M-shell can accommodate a maximum of 18 electrons, as demonstrated above. Elements with higher atomic numbers, such as transition metals, will have electrons filling the 3d subshell of the M-shell.

Conclusion:

The maximum number of electrons that can occupy the M-shell (n=3) is 18. This is determined by the sum of the maximum electron capacities of its three subshells (s, p, and d). Understanding electron configuration and the role of quantum numbers is crucial in predicting the chemical properties and behavior of elements. This knowledge is fundamental to various fields, including chemistry, materials science, and nuclear physics. Further exploration into the intricacies of atomic structure and quantum mechanics provides a deeper understanding of the universe at the atomic level, promoting scientific advancement and technological innovation.

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