<p>This is potentially the element Radium (88th element)</p>
<p>96-88 is 8 outer electron discrepancy. This most likely due to the missing elements! When we take these into account (every 15 protons from 35 (Ar) on-wards then we do end up with this amount extra outer electrons. (less neutrons therefore the we now think)</p>
<p>note there is at the end of the sequence a discrepency of 1, unsure where this comes from. there should be 1 extra missing element because the Lanthanide has 3 and not 2 missing elements in this series. Usually 2 missing element per row in the PTE starting in the Potassium row. </p>
<p>20 </p>
<p>35 (36 Ar, see structure for the discrepancy of 1)</p>
<p>50 ? - 54 ? - (80) Kr</p>
<p>95 ? - 110 ? - (125) Xe</p>
<p>140 ? - 155 ? - 170 ? - 185 ? - 200 ? - (215) Rn or is Rn the 200 element? this would make sense!! considering the isotopes of Rn. And this would make up for the error of 1 extra missing element in the end of the series!</p>