Stable nuclei

R (57% void fill)

R (34% void fill)

He⁴

1.90 r

O¹⁶

3.02 r

Ca⁴⁰

4.86r

Fe⁵⁶

5.45r

Sn¹¹⁸

6.99r

Pb²⁰⁸

8.41r