AP EAPCET 08-Jul-2022 Shift 1 Paper

Given, the radius of first orbit of Li2+‌is‌X‌Å.
Radius of nth Bohr orbit, rn=

n2h2

4π2mZe2

or rn=

0.529n2

Z

Now for Li2+=

0.529×1×1

3

Å
=

0.529

3

Å=XÅ .......(i)
Now, for He+ ion Z=2, third orbit, b=3
Radius of third orbit,
(He+)=

0.529×3×3

2

=

0.529×9

2

......(ii)
From eq (i) and (ii), the radius of the third orbit of He+(in‌Å)‌is‌

27

2

‌x.