Discovery of charged particles - class-VIII

In 1909, Rutherford discovered nucleus in his famous gold foil experiment.

Protons and neutron are present in the nucleus of the atom residing at the center.

All the mass of the atom resides in the nucleus.

The element containing greater number of proton and neutron has greater density, phosphorus has highest density as compared to others.

The size of an atom is of the order, i,e., diameter is $1A$ or $(10^{-10}m)$.
In case of the nuclear size (say He) it is in the order of 1 Fermi or near to $10^{-15} m$

The atom is made up of a central core of the nucleus with protons that are positively charged and neutrons that are neutral. The electrons revolve around this central core in orbits.

The order of magnitude of the radius of an atomic nucleus is typically measured in femtometers (or fermis), which is 10^-15 meters. In contrast, 10^-10 meters is the order of atomic size, and 10^-8 meters is molecular scale.

 Ionization Energy
The energy needed to remove one or more electrons from a neutral atom to form a positively charged ion is a physical property that influences the chemical behavior of the atom.So higher the ionization energy, higher is the stability.

As we know,

the radius of nucleus is of the order of $ {10}^{-15} $ whereas the radius of atom is of the order of  $ {10}^{-10} $.

 Mirror nuclei are nuclei where the number of protons of element one (Z1) equals the number of neutrons of element two (N2).

Protons have positive charge. In any nucleus containing two or more protons there will be electrostatic repulsion between the like charges.

All atoms except Protium, an isotope of Hydrogen contain neutrons in their nuclei. As Protium has zero neutrons in the nucleus and has mass no 1.

A free neutron is unstable and undergoes beta decay with a mean life of about 880 seconds. Protons are stable.

The density of nucleus is about $10^{10}$ times the density of atom.
This because the maximum mass of atom is concentrated in nucleus.

The particles present in the nucleus of an atom are the proton and the neutron.
Electrons are present outside the nucleus.

Hydrogen atom contains one proton in the nucleus and one electron outside the nucleus.
The space between a proton and electron in hydrogen atom is empty.

Nuclides having the same atomic and mass numbers are known as Isomers.

An atom that has an unbalanced ratio of neutrons to protons in the nucleus seeks to become more stable. The unbalanced or unstable atom tries to become more stable by changing the number of neutrons and/or protons in the nucleus. This can happen in several ways:

• converting neutrons to protons
• converting protons to neutrons
• ejecting an alpha particle (two neutrons and two protons) from the nucleus.

The nucleus of Hydrogen atom is called as proton as it has only $1$ proton in it . Thus correct answer is option C.

Nucleus is composed of protons and neutrons.

An atom has two main regions, these include nucleus and energy levels.
Nucleus contains protons and neutrons. Electrons revolve in circular energy levels.

The nucleus of the atom consists of protons and neutrons. Electrons are present in extra nuclear part.
Note: Protons, electrons and neutrons are subatomic particles.

Radius of a nucleus is proportional to $\displaystyle {A}^{{1}/{3}}$
$\displaystyle r=(1.4 \times 10^{-15}) \times {A}^{{1}/{3}}$
Where r is the radius of the nucleus with mass number A.
Here, the unit of radius is meters.  

The ratio of the volume of the atom and the volume of the nucleus is $\displaystyle 10^{15}$

The radius of an atomic nucleus is of the order of $\displaystyle {10}^{-13} cm$ or $\displaystyle {10}^{-15} m$ or one Fermi unit.

On the other hand, the radius of an atom is of the order of $\displaystyle {10}^{-8} cm$ or $\displaystyle {10}^{-10} m$ or one angstrom unit.

Note:
The radius of nucleus is much smaller than atomic radius.

The ratio of atomic radius to radius of nucleus is $\displaystyle \dfrac {{10}^{-10} m}{{10}^{-15} m}=10^5$

Volume is proportional to cube of radius.

The ratio of atomic radius to radius of nucleus is $\displaystyle  (10^5)^3 = 10^{15}$

According to Rutherford the nucleus size is ${ 10 }^{ -15 }m$.

It is the balance of protons and neutrons in a nucleus which determines whether a nucleus will be stable or unstable. Other factors that influence the stability of nucleus are binding energy and high packing fraction. 

The density of nucleus is about $2.3\times { 10 }^{ 17 }{ ㎏ }/㎥$. The density is same for all nuclei. Thus density of nucleus is of the order ${ 10 }^{ 17 }{ ㎏ }/㎥$