Name: Radiometric Dating
Uploaded: 2019-07-19
Duration: 4 min 38 s
Description: Do you know how can we estimate the age of fossils or even the age of Earth? Let us explore the key technique called radiometric dating for ageing.

Question

Why is the density of nucleus is more than that of the atom? Show that the density of nuclear matter is same for all nuclei

Accepted Answer

As the atom's almost all the mass is concentrated in the nucleus, the orbiting electrons simply increase the size of the atom by a factor of about $10^{5}$ , without adding any mass to it.Hence the density of nucleus is much more than that of the atom.

The radius of a nucleus is related to its mass number by the relation,

$R = R_{0} A^{1 / 3}$ , where $R_{0}$ is an empirical constant.and, $A$ = mass number.

As the volume of a sphere is $\frac{4}{3} {πr}^{3}$ The volume of the nucleus is $\frac{4}{3} π (R_{0} A^{\frac{1}{3}})^{3} = \frac{4}{3} π (R_{0} A)^{3}$

Hence, the volume is directly proportional to $A$ .

While density is independent of $A$ .

If the average mass of nucleons is $m$ then the total mass of the nucleus is $mA$ , Then the density of nucleus is= $\frac{mass of t h e nucleus}{volume of the nucleus} = \frac{mA}{\frac{4}{3} {πR}^{3}_{0} A} = \frac{3 m}{4 {πR}^{3}_{}} = Constant$

Hence, the density of nucleus is independent of the mass number

Why is the density of nucleus is more than that of the atom? Show that the density of nuclear matter is same for all nuclei

Important Questions on Nuclei

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