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NCERT Class XII Chapter
Nuclei
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Question : 21 of 31
Marks: +1, -0
From the relation R = R0A1/3R_0 A^{1/3}, where R0R_0 is a constant and A is the mass number of a nucleus, show that the nuclear matter density is nearly constant (i.e., independent of A).
Solution:  
Density of nuclear matter = Mass of nucleusVolume\frac{\text{Mass of nucleus}}{\text{Volume}}
ρ = A×1amu43πR3\frac{A \times 1\,\mathrm{amu}}{\frac{4}{3}\pi R^3} , where R = R0A1/3R_0 A^{1/3}
Density, ρ = A×1amu43πR03A\frac{A \times 1\,\mathrm{amu}}{\frac{4}{3}\pi R_0^3 A} = 1amu43πR03\frac{1\,\mathrm{amu}}{\frac{4}{3}\pi R_0^3} = 3amu4πR03\frac{3\,\mathrm{amu}}{4\pi R_0^3}
As R0R_0 is constant, ρ is constant
So, nuclear density is constant irrespective of mass number or size.
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