Question

3 Which elements has
(a) two shells, both of which are completely filled
with electrons ?
(1) the electronic configuration 2,8, 27
(c) a total of three shells, with four electrons in its
valence shell?
(c) 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 1

A : Neon-ne

B : Rubidium-rb

C : Boron-b

D : Carbon-c