Step-by-step explanation:
Atomic number means the number of protons an atom holds. Whereas mass number equals (number of protons + number of neutrons).
The given figure shows that there are 9 neutrons and 8 protons.
Therefore,
mass number of the atom = number of protons + number of neutrons
= 8 + 9
= 17
Hence, mass number of the atom is 17 and atomic number of the atom is 8.