An element ' $M$ ' has $25 \%$ of the electrons filled in the third shell as in the second shell. Th

Question

An element ' $M$ ' has $25 \%$ of the electrons filled in the third shell as in the second shell. The element ' $M$ ' is:\

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(b) : Element $M$ is magnesium and atomic number of magnesium is 12 . It has 2 electrons in first shell, 8 electrons in second shell and 2 electrons in third shell. Thus, it has $25 \%$ of the electrons filled in the third shell as in the second shell.\