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Estimate the average mass density of a s...

Estimate the average mass density of a sodium atom assuming its size to be about 2.5Å. (Use the known values of Avagardo's number and the atomic mass of sodium). Compare it with the mass density of sodium in its crystalline phase : `970 kg m^(-3)`. Are the two densities of the same order of magnitude ? If so, why ?

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`~= 0.7xx10^(3) km m^(-3)`. In the solid phase atoms are tightly packed, so the atomic mass density is close to the mass density of the solid.
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