Among atoms with low atomic numbers what is the neutron-proton ratio of the most stable nuclei

For low atomic number elements, the most stable ratio between protons and neutrons is 1:1. With the exception of hydrogen, most low atomic number elements' most stable forms are through this ratio. However, the ratio of protons to neutrons begin to change as the atomic number increases, with the neutrons slowly outweighing the protons in number.

Hydrogen is the most abundant element on the periodic table..hope it .

The activity series is shown in the attached picture. if the element is below the other, then you can displace the other. following the activity series as a guide, the reactions are as follows: nickel and aluminum chloride3 ni + 2 alcl₃  → 3 nicl₂ + 2 albarium and copper bromideba + cubr  →  no reaction because cu is less oxidizable than bapotassium nitrate and aluminum3 kno₃ + al  → al(no₃)₃ + 3 ksodium phosphate and zincnaso₄ + zn  → znso₄ + na