Hair is dead skin cells that pile on top of each other to "grow".
There are 30 protons and 39 neutrons in the nucleus.
This must me the isotope of an element with an atomic mass close to 69 u.
The only candidates are Zn and Ga.
Zn has a zinc-69 isotope with mass 68.926 u.
Ga has a gallium -69 isotope with mass 68.925 u.
The isotope is probably

.
It has 30 protons and 39 neutrons.
Answer: The nonpolar covalent bond happens in an O₂ molecule.
Explanation: Nonpolar bonds happen where there's no difference between the polarity of the atoms involved. This usually happens when the same atoms bond to each other, which explains why the O₂ molecule is the one who has this bond.
Well you didn’t post any but I’m hoping that either plastic, lead, wood, glass, or paper, are an option.