The atomic number of an element is 26. How many electrons are present in M- Shell of this element in ground state?

Explanation

The correct option is b) 14.To determine the number of electrons present in the M-shell of an element with an atomic number of 26, we need to determine the electron configuration of the element.The atomic number 26 corresponds to the element iron (Fe). The electron configuration of iron is:1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁶In the ground state, all the lower energy levels (shells) will be filled before the M-shell. Therefore, the M-shell represents the 3rd shell (n=3). The M-shell consists of the 3s, 3p, and 3d subshells.The 3s subshell can hold a maximum of 2 electrons, the 3p subshell can hold a maximum of 6 electrons, and the 3d subshell can hold a maximum of 10 electrons.To determine the number of electrons in the M-shell, we need to add up the electrons in the 3s, 3p, and 3d subshells.3s² + 3p⁶ + 3d⁶ = 2 + 6 + 6 = 14Therefore, in the M-shell of iron (Fe) in its ground state, there are 14 electrons.Hence, the correct option is b) 14. The other options (a, c, d) are incorrect because they do not represent the correct number of electrons in the M-shell of iron.