A stable isotope has just<em> the right number of neutrons for the number of protons </em>(the <em>n:p ratio</em>) to hold the nucleus together against the repulsions of the protons.
A radioactive isotope has either too few or too many neutrons for the nucleus to be stable,
The nucleus will then emit <em>alpha, beta, or gamma radiation</em> in an attempt to become more stable.
Answer: 54 atm
Explanation:
I did 67/82.5 then got 0.8121212121. I them divided 44 by 0.81212121 and got 54.1791044776