An atom of an element has two electrons in the outermost M-shell. State
(i) electronic configuration
(ii) atomic number
(iii) number of protons
(iv) valency of this element
(i) Electronic configuration = K,L,M 2, 8, 2
(ii) Atomic number = 2 + 8 + 2=12
(iii) Number of protons = 12
(iv) 2, because there are 2 valence electrons, which it can lose easily to achieve stable outermost electronic configuration.