Which of the following must be the same for two isotopes of an element?
a. the number of neutrons
b. the atomic number
c. the mass
d. the charge

<<<<<<<<<< B is the answer >>>>>>>

32: from largest to smallest, this hierarchy includes eons, eras, periods, epochs, and ages.

33: answer is c

i really hope this answer you out! it makes my day people like you and giving back to the community that has me through school! if you could do me a favor, if this you and this is the very best answer and you understand that all of my answers are legit and top notch. mark as brainliest! and have a awesome day!