Answer:
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Explanation:
<h2>Packing fraction is defined as a way of expressing the variation of isotopic mass from whole mass number (atomic mass). This fraction can have positive or can have negative sign. A positive packing fraction describes a tendency towards instability.</h2><h2>The equation for packing fraction is: Packing fraction = (N atoms) x (V atom) / V unit cell. N atoms is the number of atoms in a unit cell. V atom is the volume of the atom, and V unit cell is the volume of a unit cell. Substitute the number of atoms per unit cell into the equation.</h2>
The statement that does not describe elements would be that they can be separated by a chemical reaction. This is not the case, an element is a pure substance that can't be degraded into any other constituent that would form it. They are building blocks composed by atoms.
Neutrons + protons = atomic mass number
I hope this helps!
