The standard size of an atom is <span>1 X 10 -8 cm.
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The percentage of atoms in the universe that are hydrogen are 90%
The formula for water is H2O so there would have to be two Hyrdogens and one oxygen. Therefore it would be 4g of Hydrogen and 16g of Oxygen leaving you with 20g.
The answer is D.
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Magnesium element exists as single atoms. Free oxygen is always diatomic (two atoms bonded together) as O2. Nitrogen gas is also diatomic N2.
2Mg + O2 → MgO
Mg forms a +2 ion, O forms a -2 ion, so they combine and balance in a 1:1 ratio. MgO, magnesium oxide, is a solid.
3Mg + N2→Mg3N2
Mg forms a +2 ion, but N forms a -3 ion. Hence the Mg3N2 configuration for magnesium nitride.