Answer:atomic and mass number
Explanation:
Radioactive decay process is a type of process in which a less stable nuclei decomposes to a stable nuclei by releasing some radiations or particles like alpha, beta particles or gamma-radiations. The radioactive decay follows first order kinetics.
General representation of a radioactive nuclide is given as:
where,
Z represents Atomic number
A represents Mass number
X represents the symbol of an element
Thus atomic and mass numbers are shown in the symbol for a radioactive nuclide.
First of all, as you seen the gases are noble which means that will not react with each other and in this case each gas create individual pressure.
P= total pressure
P = pressure of neon
P = pressure of argon
P = pressure of helium {which is required}
P = P
+ P
+ P
1.25 = 0.68 + 0.35 + P
P = 1.25 - [0.68 + 0.35] = 0.22 atm