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 ?
The positions of three elements A, B and C in the periodic table are shown below:
(a) State whether A is a metal or non-metal.
(b) State whether C is more reactive or less reactive than A.
(c) Will C be larger or smaller in size than B?
(d) Which type of ion, cation or anion, will be formed by element A ?