whats the increasing order of ionic radii of the following I-1 , N-3 , S-2 , Cl-1 , Se-2 ?
Answers
Answer:
If the ions derived from different atoms are isoelectronic species, then they all have same number of electrons in their electronic shells and will have got same electronic configuration but their nuclear charge will differ because of their difference in number of protons in the nucleus. With increase in number of protons in the nucleus the electrons are more attracted towards nucleus thereby causing the decrease in ionic radius. On this principle our problem will be solved
The given ions are
7
N
-3
→
no. of proton
=
7
and
no of electron
=
10
8
O
-2
→
no. of proton
=
8
and
no of electron
=
10
9
F
-
→
no. of proton
=
9
and
no of electron
=
10
11
N
a
+
→
no. of proton
=
11
and
no of electron
=
10
12
M
g
-3
→
no. of proton
=
12
and
no of electron
=
10
Hence the increasing order of ionic radius is
12
M
g
-3
<
11
N
a
+
<
9
F
-
<
8
O
-2
<
7
N
-3
To rmember ->For isoelectronic species lower the nuclear charge higher the radius