<span>The hardest known mineral is diamond.
</span>
Answer:
Explanation:
Its just dangerous stuff can go in the air and harm others
The atomic radius of main group elements generally increases down a group because as there are more electrons they are farther away from the nucleus and the electrons closer to the nucleus shield the outer electrons from the protons for attraction.
19.927 moles are in 1.20 times 
atoms of phosphorus.
<h3>What are moles?</h3>
A mole is defined as 6.02214076 ×
of some chemical unit, be it atoms, molecules, ions, or others.
1 mole of any substance contain Avogadro's number of molecules so we can calculate the number of moles by dividing the provided number of atoms over Avogadro's number to obtain the number of moles .
Moles= 
Moles= 1.20 X atoms ÷ 6.022 X
= 19.927
Hence, 19.927 moles are in 1.20 times atoms of phosphorus.
Learn more about moles here:
brainly.com/question/26416088
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Answer:
The rule is especially applicable to carbon, nitrogen, oxygen, and the halogens, but also to metals such as sodium or magnesium. ... All four of these electrons are counted in both the carbon octet and the oxygen octet, so that both atoms are considered to obey the octet rule.
