You can determine this by counting the number of electrons on the last orbital. If the number of electrons on the last orbital (valence electrons) is 8 then it satisfies the octet rule because the compound has mirrored the look of a noble gass or “neutral” charge.
Answer:
Xenon
Explanation:
Avogadro’s number represent the number of the constituent particles which are present in one mole of the substance. It is named after scientist Amedeo Avogadro and is denoted by
.
Avogadro constant:-

Let the molar mass of the element is x g/mol
So,
atoms have a mass of x g
Also,
atoms have a mass of
g
This mass is equal to 848 g
So,

x= 131.3 g/mol
This mass correspond to xenon.
Answer:
Valence electrons of selenium will be placed in s and p-orbitals.
Explanation:
Hope this helps.
Answer: avogadros number/constant
Explanation: