(i) How do you calculate the possible valency of an element from the electronic configuration of its atoms? (ii) Calculate the valency of element X whose atomic number is 9
(i) The valency of an element is determined by the number of electrons present in the last shell. If a number of valence electrons are less than or equal to 4 then, valency = a number of valence electrons. If, the number of valence electrons greater than 4 then, valency = 8 – number of valence electrons. (ii) The electronic configuration of element X with atomic number 9 is 2,7 Valency of X = 8−7 =1 Hence, the valency of the element with atomic number 9 is 1.
