Question

Indicate how many electrons must be gained or lost by each of the following achieve a stable electron configurations.

Answer 1

a) Strontium has 38 electrons.

Its electronic configuration is,

$\begin{gathered} Sr-1s^22s^22p^63s^23p^64s^23d^{10}4p^65s^2 \\ =\lbrack Kr\rbrack5s^2 \end{gathered}$

As it can be seen, the valency of strontium is 2. Thus it needs to lose 2 electrons to be stable.

Thus the answer is '2 lost'.

b) The atomic number of antimony is 51. The electronic configuration of antimony (Sb) is

$Sb=\lbrack Kr\rbrack4d^{10}5s^25p^3$

Thus The