360 seconds?
i’m guessing that is the answer as the question is unreasonable
C. An atom of helium has its valence electrons in its first energy level, it wouldn't and can't satisfy the Octet rule as it only has 2 electrons, but with 2, it has a full shell, as the first energy level can hold only 2 electrons.
<span>number of moles are the amount of substance of an element .
number of moles can be calculated as follows;
number of moles = mass present / molar mass of element
molar mass of Ar - 40 g/mol
number of moles of Ar = 22 g / 40 g/mol = 0.55 mol .
there are 0.55 mol of Ar</span>
<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>
