From Fresh Dictionary
English
Noun phrase
Oddo-Harkins rule
- ((chemistry{{#if:|, {{{2}}}{{#if:|, {{{3}}}{{#if:|, {{{4}}}{{#if:|, {{{5}}}{{#if:|, {{{6}}}{{#if:|, {{{7}}}{{#if:|, {{{8}}}{{#if:|, {{{9}}}}}}}}}}}}}}}}}}})) a rule which states that elements that have an even number of protons in the nucleus are more common than those with an odd number
