Home > Chemistry > Periodic Trends in Ionic Size

In increasing order, how would you rank these ions according to ionic radius? #Sr^+2#, #Br^-#, #Rb^+#, #As^-3#, #Se^-2#

Answer 1

Can you not get your Periodic Table, and classify the ions according to size?

It is well known that for #"NEUTRAL atoms"#, size DECREASES across a Period from left to right as we face the Table, and INCREASES down a Group.

Try your hand at it and report back here. For parent atoms in the same Period, anionoids will be larger intrinsically because electrons are added to the valence shell, which expands, and cations will be smaller intrinsically because a valence shell may be removed entirely.

By signing up, you agree to our Terms of Service and Privacy Policy

Answer 2

Xavier Avery

In increasing order of ionic radius:

As^-3 < Se^-2 < Br^- < Sr^+2 < Rb^+

By signing up, you agree to our Terms of Service and Privacy Policy

Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.