Size of the Nucleus Video Lecture | Physics Class 12 - NEET

hi in this video I'll explain about the
size of a nucleus using a representative
animation of a nucleus and an atom you
can see an electron that's orbiting on
the periphery of an atom and at the
center of the atom you can see a nucleus
comprising of one proton shown in red
color and there's a positive sign on it
and there are three neutrons of
yellowish color and all of these things
the proton and neutrons are rotating
about some axis that's a spinning and
angular momentum that's a different
subject we're talking about size here in
this particular video and nobody has
actually seen a nucleus now in direct
experiments but scientists give an
equation R or the radius of a nucleus is
equal to r0 into a to the power 1 by 3 R
0 is a constant 1 point 1 into 10 to
power minus 13 meters it's a very very
small number and a is the mass number of
the nucleus and we know that that mass
number is equal to the number of protons
z plus number of neutrons n so therefore
it's logical that the radius of a
nucleus is proportional to the mass
number to the power of 1 by 3 to find
the volume of a nucleus an important
assumption is made that it is a sphere a
ball it's also assumed that protons and
neutrons are spheres this assumption was
made to make things easy although in
real life nobody has actually seen any
of these things through the most
powerful telescope so with the
assumption of a sphere V is 4 by 3 PI R
cubed substitute for RS r0 e to the
power 1 by 3 whole cubed then you get 4
by 3 PI into r0 whole cubed and inside
the brackets a to the power 1 by 3 whole
cube becomes just a now r0 is a constant
so basically the volume V becomes
proportional to a and that's logical
now just a small word on the atom itself
you saw in the animation a nucleus and
an atom which is much larger than the
nucleus in reality the atom is more than
ten thousand times the radius R the
nucleus now that means that there's a
lot of empty space between the central
nucleus and the outer periphery of the
atom that's true and even in the Alpha
scattering experiment you might have
seen that most of the alpha particles
that bombarded atoms just went through
the atoms without any deviation and only
a few particles got deviated when they
hit the small nucleus at the center of a
very large atom the atom shape is also
assumed to be a sphere only to make
things simple although in real life the
shape of the atom is a subjective
research and it need not be a perfect
sphere at all I hope this video was
useful to you thanks and have a great
day