Yes magnesium is a pure substance and it is a element.
An oxide of nitrogen contains 30.45 mass % N, if the molar mass is 90± 5 g/mol the molecular formula is N₂O₄.
<h3>What is molar mass?</h3>
The molar mass of a chemical compound is determined by dividing its mass by the quantity of that compound, expressed as the number of moles in the sample, measured in moles. A substance's molar mass is one of its properties. The compound's molar mass is an average over numerous samples, which frequently have different masses because of isotopes.
<h3>How to find the molecular formula?</h3>
The whole-number multiple is defined as follows.
Whole-number multiple = 
The empirical formula mass is shown below.
Mw of empirical formula = Mw of N+ 2 x (Mw of O)
= 14.01 g/mol + 2 x (16.00 g/mol)
= 46.01 g/mol
With the given molar mass or the molecular formula mass, we can get the whole-number multiple for the compound.
Whole-number multiple =
≈ 2
Multiplying the subscripts of NO2 by 2, the molecular formula is N(1x2)O(2x2)= N2O4.
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Answer:
Explanation:
Chemical properties of atoms relies solely on the number of electrons they contain, more particularly, the valence or outermost electrons in the orbit round the nucleus of an atom.
A neutral atom is one that has not gained or lost electron or even shared electrons with any other atom.
On close examination of how electrons are distributed in the orbits of an atom, we can know if an atom will gain or lose electrons in a reaction. This is very important in determining the chemical properties of an atom.