Answer: 
Explanation:
Electronic configuration represents the total number of electrons that a neutral element contains. We add all the superscripts to know the number of electrons in an atom.
The electrons are filled according to Afbau's rule in order of increasing energies and thus the electronic configuration for Hafnium with atomic number of 72 and containing 72 electrons is:

The electronic configuration for Hafnium in terms of nearest noble gas Is
![[Xe]6s^24f^1{14}5d^2](https://tex.z-dn.net/?f=%5BXe%5D6s%5E24f%5E1%7B14%7D5d%5E2)
Hey there!
I am not the greatest in this subject but I believe that 2C2H2+502 is balanced!
If i am incorrect, I am very sorry and would love any feedback!
Hope i made your day easier.
Have a nice day and happy Halloween!
The mass numbers of the different isotopes of that element are averaged according to their respective abundances in nature.
Scientific law = Describe what phenomena happen , Theory = Explains why phenomena occur