Answer:
16 is the mass number. 8 is the atomic number.
The density at 1,291 km from the surface of the planet is
[ (1,291 - planet's radius)/(planet's radius) ] ^ some power .
<span>Of all the sub-shells shown ( 1s ,2s ,2p ,3s ,3p ,4s ,3d ,4p ,5s ,4d ,5p ,6s ,4f ,5d) the ones that act as core orbital of HF (Hydrogen Fluoride) is 6s and 5d</span>
This equation is balanced.