Which element has :
(a) two shells, both of which are completely filled with electrons ?
(b) the electron 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 ?
(a) Neon (2, 8) has two shells which are completely filled with electrons.
(b) Magnesium has electron configuration (2, 8, 2).
(c) Silicon (2, 8, 4) has three shells and four electrons in its valence shell.
(d) Boron (2, 3) has two shell and three electrons in its valence shell.
(e) Carbon (2, 4)