Mass of the nuclues that is (proton +neutron) of that element.
Enjoy what you have,
in the future there is no more gender.
Procreation limits to zero.
They already are equal...If you want to compare not equal than look at the middle east...By the way in my view "femenizim" is not about equality as I hear so much, there is a different word for that, and most feminist I meet are crazy over the top cisphobic...