Give a general introduction to the nucleus.
Give a general introduction to the nucleus.
In every atom the positive charge and mass are densely concentrated at the centre of the atom which is called the nucleus of the atom.
The dimensions (radius) of a nucleus are much smaller than those of an atom.
Experiments on scattering of $\alpha$-particles demonstrated that the radius of a nucleus was smaller than the radius of an atom by a factor of about $10^{4}$.
$\frac{\text { Volume of nucleus }}{\text { Volume of atom }}=\frac{4 / 3 \pi \times\left(10^{-14}\right)^{3}}{4 / 3 \pi \times\left(10^{-10}\right)^{3}}=10^{-12}$
$\therefore$ The volume of a nucleus is about $10^{-12}$ times the volume of the atom.
Even so the nucleus contains most (more than $99.9 \%$ ) of the mass of an atom. If we think of a atom is enlarged to the size of a classroom, the nucleus would be the size of pinhead.
Hence, the empty in the atom is a very large area.
Similar Questions
Describe the nuclear force and its characteristics.
Describe the nuclear force and its characteristics.
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?
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?
- [KVPY 2017]
Assertion : Isobars are the elements having same mass number but different atomic number.
Reason : Neutrons and protons are present inside nucleus.
Assertion : Isobars are the elements having same mass number but different atomic number.
Reason : Neutrons and protons are present inside nucleus.
- [AIIMS 1997]
Explain isotopes, isobar, isotones and isomers by giving examples.
Explain isotopes, isobar, isotones and isomers by giving examples.
If the mass number of an atom is $A = 40$ and its electron configuration is $1{s^2},\;2{s^2},\;2{p^6},\;3{s^2},\;3{p^6}$, the number of neutrons and protons in its nucleus will be
If the mass number of an atom is $A = 40$ and its electron configuration is $1{s^2},\;2{s^2},\;2{p^6},\;3{s^2},\;3{p^6}$, the number of neutrons and protons in its nucleus will be