Which element has (a) two shells, both of which are completely filled with electrons? (b) the electronic configuration 2, 8, 2? (c) a total of three shells, with four electrons in its valence shell? (d) a total of two shells, with three electrons in its valence shell? (e) twice as many electrons in its second shell as in its first shell?
(i) Neon has two shells, both of which are completely filled with electrons (2 electrons in K shell and 8 electrons in L shell). (ii) Magnesium has the electronic configuration, 2, 8, 2. (iii) Silicon has a total of three shells, with four electrons in its valence shell (2 electrons in K shell, 8 electrons in L shell and 4 electrons in M shell). (iv) Boron has a total of two shells, with three electrons in its valence shell (2 electrons in K shell and 3 electrons in L shell). (v) Carbon has twice as many electrons in its second shell as in its first shell (2 electrons in K shell and 4 electrons in L shell).
