Final answer:
Hafnium-176 (Hf-176) has 72 protons and 104 neutrons.
Step-by-step explanation:
The student is asking about the number of protons and neutrons in an atom of Hafnium-176 (Hf-176).
The atomic number of Hafnium (Hf) is 72, which tells us that it has 72 protons.
The mass number of Hf-176 is 176, which is the sum of protons and neutrons in the nucleus.
To find the number of neutrons, subtract the number of protons from the mass number: 176 - 72 = 104 neutrons. Therefore, Hf-176 has 72 protons and 104 neutrons.