Question

Name a species that will be isoelectronic with each of the following atoms or ions :
(1) Ne (it) C (iii) Ca2+ . (iv) Rb.
Arrange the following ions in the order of increasing size :​

Answer 1

• c<ca2+<Rb<Ne

this is the correct sequence

Answer 2

Answer:

1) O2-

2)O2+

3)Ar

4)Br- ( the last question may be Rb+ with 36 electrons, since that is the possible one. )

-------------

For the second part of the question, the increasing order of their size is as follows:

C < Ca2+ < Rb < Ne

Explanation:

What are isoelectronic species?

What are isoelectronic species?They are the species with same no. of electrons.

From the above definition,

1) Ne has 10 electrons.

Thus all the species with 10 electrons could be isoelectronic with Ne.

Eg. O2- ( 8 + 2)

Al3+ ( 13 - 3)

Na+ ( 11- 1) and many more species.....

2) C has 6 electrons.

Thus all the species with 6 electrons could be isoelectronic with C.

Eg. O2+( 8-2)

Similarly you can calculate all other questions.

----------------------

And for the second part,

Carbon has the smallest size since as we move from left to right across the period, the size decreases.

This is an exception for noble gases-- hence Ne has the largest size.

Ca 2+ comes next due to the same reason plus, the fact that size increases down the group.

Rb comes next with Ne as the largest amongthe given species.

----------------------

I hope it helped!!

♤♧♧♤