Question

Question 34
Fill in the blanks in the following statements.
(a) Rutherford's alpha-particle scattering experiment lead to the discovery of the ___
(b) Isotopes have the same ___ but different ___
(c) Neon and chlorine have atomic numbers 10 and 17 Their valencies
will be ___ and ___ respectively.
(d) The electronic configuration of silicon is ___ and that of sulphur is ___

Answer 1

(a) nucleus.
(b) atomic number, mass number.
(c) zero, one.
${}_{10}Ne-$ Electronic configuration 2, 8. Its outermost shell is completely filled. Hence, its valency is zero.
${}_{17}Cl-$ 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.