[enantiomorph]

Hi there, I have a question involving ranking the sizes of ions from largest to smallest.  I know the trends and I've made some searches over the internet, but I've yet to determine the correct answer.  I was wondering if anyone here may please offer me a hand.  Thank you!

Question:
Order the following sets of ions accordingly from largest to smallest
A. Cl^-
B. Be²⁺
C. Li⁺
D. F^-
E. H^-

I've found that chloride = 0.01 nm, fluoride = 0.136 nm, Li = 0.060 nm, and Be = 0.031 nm.  However, I cannot find the ionic radius of hydride anywhere nor can I predict it with the trend.  What do you guys think?

[Bakegaku]

chloride = 0.01 nm, fluoride = 0.136 nm, Li = 0.060 nm, and Be = 0.031 nm.

Chloride is smaller than beryllium?  What source did you use to find these numbers?

[mdlhvn]

Yeah, I think enantiomorph have read from a incorrect soure. However, it's not necassary to know exactly the radius of each ion. You should the common trend in periodic table, that is, in the same period, the radius of atom decreases from the left to the right and in the same column, that of atom increase from the top to the bottom.

With ion, the rules is:
If ions have same electron configuration, then the radius dereases via the increase of nuclear charge..
And of course, ions having more electron classes will have the larger  radius.

In your question:
A. Cl-, 3 classes
B. Be2+, 1 class, p=4
C. Li+, 1 class, p=3
D. F-, 2 classes,
E. H-, 1 class, p=1

Then the order is Cl-, F-, H-, Li+, Be+.

 

[enantiomorph]

Oops, sorry about that I made a typo.  It should be chloride = 0.181 nm, fluoride = 0.136 nm, Li = 0.060 nm, and Be = 0.031 nm

However, I heard there was some controversy in the actual ionic radius of hydride.  According to this website http://boomeria.org/chemtextbook/cch11.html they say H^- has a radius of 0.142 nm.  Are they right or is mdlhvn more accurate?

Thanks again to everyone for your help.