Order of magnitude of density of uranium nucleus is $({m_p} = 1.67 \times {10^{ - 27}}kg)$
${10^{20}}kg/{m^3}$
${10^{17}}kg/{m^3}$
${10^{14}}kg/{m^3}$
${10^{11}}kg/{m^3}$
Assertion : Isobars are the elements having same mass number but different atomic number.
Reason : Neutrons and protons are present inside nucleus.
Write the formula for the average radius of nucleus.
Consider the following statements ( $X$ and $Y$ stand for two different elements):
$(I)$ ${ }_{32}^{65} X$ and ${ }_{33}^{65} Y$ are isotopes.
$(II)$ ${ }_{42}^{86} X$ and ${ }_{42}^{85} Y$ are isotopes.
$(III)$ ${ }_{85}^{174} X$ and ${ }_{88}^{177} Y$ have the same number of neutrons.
$(IV)$ ${ }_{92}^{235} X$ and ${ }_{94}^{235} Y$ are isobars.
Which of the above statements are correct?
The ratio of the density of oxygen nucleus $\left({ }_8^{16} O \right)$ and helium nucleus $\left({ }_2^4 He \right)$ is
$\pi $ mesons can be