question_answer 16)

               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 ? 

Answer:

(a) Neon, Ne (2, 8)                                                          (b) Magnesium, Mg (2, 8, 2) (c) Silicon, Si (2, 8,4)                                                       (d) Boron, B (2, 3) (e) Carbon, C (2,4)