Table of Isobars
Not the Segre Chart
Many people just do not get the gist of The Incremental Table of Atomic Isobars. I present the idea that Hydrogen in its three forms that occur naturally, two of which are stable, comprise more that 90%, by mass, of the universe. This makes Hydrogen-1, the most common isotope, the most abundant Isobar in the cosmos. The stability of Hydrogen with its single proton is vastly orders of magnitude above the stability of any other isobar. Hydrogen-2 is stable but not abundant. Hydrogen-3 is radioactive (with a half-life of 12.33yrs.) and is less abundant more so.

H 1    
  H 2  
    H 3

Arranging the species of hydrogen in this fashion allows us to observe how the number of nucleons relate to atomic stability much more so than we would see in the chart at this link that is provided by the US government. It is a very useful chart and you should use it often. The Trilinear Chart of the Nuclides used hexagons and is no longer in print. A third chart called the Segre Chart is very useful to chemistry but none of the three versions lend to metaphor of a geometric basis to stability and durablity.

Helium is the second most abundant element 0.000137% of which is the Helium-3 flavor. Helium-4 while not as stable as the single proton of Hydrogen-1 is still stable by orders of magnitude above all other atomic nuclei. Consider the radioactive decay of practically all heavy elements beyond Bismuth-209, in particular Uranium-238 is by the means of emission of an alpha particle, 92U238 —> 90 Th234 + 2He4, which is essentially a Helium-4 nucleus.

A visit to Blase Labs now is a good idea.
The Particle - The wrong turn that led physics to a dead end

H 1    
  H 2  
He 3   H 3
  He 4  

Again by arranging the species of helium in a fashion corresponding with the proton/neutron ratios with that thus far depicted allows us to observe how the number of nucleons of each nuclide relate to atomic stability. The chart laid out thusly can accommodate the addition of useful information, also we can include entities like Hydrogen-4 which can exist in the laboratory but do not hang around for very long.
H 001

  H 002

He 003

  H 003
12.33 yr
  He 004

  H 004
5.42 MeV
n,2.980 MeV
Entities in a column all share the same proton/neutron ratio while those in the same row are Isobars.
(nuclides of roughly the same atomic weight but different elements)
(having the same number of nucleons)
see Binding Energy
The blocks holding H-1 and He-4 are marked off with yellow to denote these "nuclides" as SUPER Stable.

Please if you would care to guess what the Third most abundent Element in the universe is?

Let's put that a different way, Where on this chart would you expect to see the next most abundent Element placed?
n=p-1 n=p n=p+1 n=p+2 n=p+3 n=p+4
H 1          
  H 2        
He 3   H 3      
  He 4        
  C 12        
  N 14        
  O 16        
  Ne 20