Tag: the plum pudding atom

Questions Related to the plum pudding atom

The nucleus of the hydrogen atom is called as:

  1. neutron

  2. electron

  3. proton

  4. nucleons


Correct Option: C
Explanation:

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 two kinds of subatomic particles: 

  1. protons and neutrons

  2. electrons and neutrons

  3. protons and electrons

  4. none of the above


Correct Option: A
Explanation:

Nucleus is composed of protons and neutrons.

An atom has two main regions. Which are those?

  1. Planetary electrons and energy levels

  2. Nucleus and kernel

  3. Principal energy levels and energy sublevels

  4. Nucleus and energy levels


Correct Option: D
Explanation:

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:

  1. protons and neutrons

  2. protons and electrons

  3. neutrons and electrons

  4. protons, neutrons and electrons


Correct Option: A
Explanation:

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:

  1. $A$

  2. ${A}^{{1}/{3}}$

  3. ${A}^{2}$

  4. ${A}^{{2}/{3}}$


Correct Option: B
Explanation:

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:

  1. ${10}^{10}$

  2. ${10}^{12}$

  3. ${10}^{15}$

  4. ${10}^{20}$


Correct Option: C
Explanation:

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 $\displaystyle  (10^5)^3 = 10^{15}$

Size of the nucleus is:

  1. $1A^0$

  2. $10^{-16}m$

  3. $10^{-15}m$

  4. $10^{-14}m$


Correct Option: C
Explanation:

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

Size of the atom ranges from $0.1$to $0.5nm$ 

Which is characteristic of unstable nucleus?

  1. $n/p$ ratio is high

  2. Low binding energy

  3. High packing fraction

  4. None of these


Correct Option: A,B,C
Explanation:

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. 

So, the characteristics of unstable nucleus are
  1. $\dfrac{n}{p}$ ratio is high
  2. Low binding energy
  3. High packing fraction

The density of nucleus is of the order of:

  1. ${ 10 }^{ 5 }kg{ m }^{ -3 }$

  2. ${ 10 }^{ 10 }kg{ m }^{ -3 }$

  3. ${ 10 }^{ 17 }kg{ m }^{ -3 }$

  4. ${ 10 }^{ 25 }kg{ m }^{ -3 }$


Correct Option: C
Explanation:

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 ${ 10 }^{ 17 }{ ㎏ }/㎥$

The radius of nucleus is:

  1. proportional to its mass number

  2. inversely proportional to its mass number

  3. proportional to the cube root of its mass number

  4. not related to its mass number


Correct Option: C
Explanation:
The radius of a nucleus (r) is proportional to the cube root of its mass number (A).
The approximate law is $r = r _0 \times A^{ 1/3 }$
where $r _0 = 1.2 \times 10^{ -15 }\ m$
option C is correct