Whats the Atomic Symbol for the following element

Z= 7 , Number of Neutrons = 15

(explain answer thanks)

Z = 7 means 7 protons, so the element is Nitrogen, N.

Since they list the number of neutrons you might be looking for 22N the name of the particular isotope. The symbol N specifies z=7 and the 22 gives the total number of nuclei (protons + neutrons).