Given,
The number of the neutrons in the isotope, N=19
The atomic number of phosphorous is Z=15.
Thus the atomic mass number is the sum of the protons and the neutrons in the atom.
Thus the mass number of the phosphorous-19 is
[tex]A=Z+N[/tex]
That is,
[tex]\begin{gathered} A=15+19 \\ =34 \end{gathered}[/tex]
Thus the symbol of the phosphorus-19 is
[tex]^{34}_{15}P[/tex]
