<p>Beryllium 9 is the only stable isotope. </p>
<p>The shape shows clearly how it resembles two intertwined Lithium's. These 2 rings of 5 protons are equated with the valence number possibilities. In this case + 2. Beryllium valence value as nuclet in the heavier element tends to be either + 1 or +2 Beryllium itself has all the room needed to make a default connection of +2. In heavier elements the valence number can vary for several reasons such as An extra neutron on an nuclet, a particular chemical combination, or literally missing connection points. The potential of more to be understood here is a real possibility. <br />
Beryllium is in effect a geometric 'in between state' between Lithium and Carbon.</p>
Atomic Structure
N0:
state: beryllium
protons:
P1:
P3: {color: neutron}
P4:
P5:
P6:
P7:
P9:
P10:
P11:
electrons:
E01: {protons: [P4, P5]}
E02: {protons: [P10, P11]}
E03: {protons: [P6, P7]}
E04: {protons: [P9, P1]}
Notes
<p>The inner electrons are responsible for (causing) the densest packing.</p>
<p>The Li 8 / Be8 configuration decays into 2 helium nuclei</p>
<p>When looking at Li with the 3 pairs (and 1 extra n) in the pentagonal bipyramid shape we see that 2 pairs are more or less a helium and the 3 rd pair added onto it. Looking at Be8 we can see that 2 pairs want to come closer in a denser packed state and form a helium shape also. Since nothing is balancing this force out the Be8 decays! </p>
<p>When we add one more 'neutron', we see that in Be 9 there is more balance and the element is stable now. </p>
