question_answer 68)

  Fill in the blanks in the following statements. (a) Rutherford's a-particle scattering experiment lead to the discovery of the.......... (b) Isotopes have same ......... but different........... (c) Neon and chlorine have atomic numbers 10 and 17 respectively. Their valencies will be ......... and ......... respectively, (d) The electronic configuration of silicon is ......... and that of sulphur is

Answer:

  (a) nucleus. (b) atomic number, mass number. (c) zero, one. Electronic configuration 2, 8. Its outermost shell is completely filled. Hence, its valency is zero.  Electronic configuration 2, 8, 7 It can complete its outermost shell by gaining 1 electron. Hence, its valency = 1 (d) 2, 8, 4 and 2, 8, 6.