There are 30 protons and 39 neutrons in the nucleus.
This must me the isotope of an element with an atomic mass close to 69 u.
The only candidates are Zn and Ga.
Zn has a zinc-69 isotope with mass 68.926 u.
Ga has a gallium -69 isotope with mass 68.925 u.
The isotope is probably

.
It has 30 protons and 39 neutrons.
Markovnikov rule, in organic chemistry, a generalization, formulated by Vladimir Vasilyevich Markovnikov in 1869, stating that in addition reactions to unsymmetrical alkenes, the electron-rich component of the reagent adds to the carbon atom with fewer hydrogen atoms bonded to it, while the electron-deficient component ...
Im guessing it might be 98.4x0.58, when you rearrange the pressure formula.
When you are tuning an instrument it changes the sound of the instrument