Question: 1)The atomic no. Of chlorine is 17. Give its number of valence electrons and valency. Solution:  Atomic No. Of Chlorine = 17 Electronic Configuration = 2, 8, 7 Now, Valence Electrons = No. Of electrons present in outermost shell, orbit or energy level. Therefore, Valence electrons of chlorine = 7 Valency of Chlorine = (8-7) = 1 Question: … Continue reading CL9:SA-2(Science)Question_Paper_ Solved(2015-2016)