Introduction Of Nucleus, Isotopes, Isobars, Isotones, A.M.V, Mass Defect, Binding Energy​ (NEET LEVEL)

1.

Calculate the binding energy of a deutron. Given that

mass of proton = 1.007825u

mass of neutron = 1.008665u

mass of a deutron = 2.014103u.

(a) 2.2 MeV

(b) 3.94 MeV

(c) 2.44 MeV

(d) 0.3 MeV

Ans (a)

2.

If element with principal quantum number n> 4 were not allowed in nature, the number of possible elements would be

(a) 60

(b) 31       

(c) 4  

(d) 64.

Ans  (a)

3.

In stable nuclei, the number of neutrons (N) is related to the number of electrons (Z) in the neutral atom in general as

(a) N > Z  

(b) N = Z  

(c) N < Z  

(d) N ³ Z.

Ans  (d)

4.

When a lithium nucleus (₃Li⁷) is bombarded with certain particles, only two alpha particles are produced. The bombarding particles are

(a) photons                                   

(b) electrons                                 

(c) protons                                     

(d) deutrons.

Ans (c)

5.

From the following equations pick out the possible nuclear fusion reactions

(a) _{\text{6}}{{\text{C}}^{{\text{13}}}}+{{\,}_{\text{1}}}{{\text{H}}^{\text{1}}}\to {{\,}_{\text{7}}}{{\text{N}}^{{\text{14}}}}+\text{4}\text{.3MeV}         

(b) _{\text{6}}{{\text{C}}^{{\text{12}}}}+{{\,}_{\text{1}}}{{\text{H}}^{\text{1}}}\to {{\,}_{\text{7}}}{{\text{N}}^{{\text{13}}}}+\text{2}\,\text{MeV}

(c) _{\text{7}}{{\text{N}}^{{\text{14}}}}+{{\,}_{\text{1}}}{{\text{H}}^{\text{1}}}\to {{\,}_{\text{8}}}{{\text{O}}^{{\text{15}}}}+\text{7}.3\,\text{MeV}      

(d) _{{\text{92}}}{{\text{U}}^{{\text{235}}}}+{{\,}_{\text{0}}}{{n}^{\text{1}}}\to {{\,}_{{\text{54}}}}\text{X}{{\text{e}}^{{\text{140}}}}+{{\,}_{{38}}}\text{S}{{\text{r}}^{{94}}} +2\,{{(}_{0}}{{n}^{1}})+\gamma +200\text{MeV}\text{.}

Ans (b)

6.

The mass number of He is 4 and that for sulphur is 32. The radius of sulphur nucleus is larger than that of helium by times

(a) \sqrt{8}

(b) 4  

(c) 2  

(d) 8.

Ans (c)

7.

M, M_n and M_p denote the masses of a nucleus _ZX^A, a neutron and proton respectively. If the nucleus is separated into its individual protons and neutrons then                                        

(a) M=(A-Z){{M}_{n}}+Z{{M}_{p}}                      

(b) M=Z{{M}_{n}}+(A-Z){{M}_{p}}

(c) M>(A-Z){{M}_{n}}+Z{{M}_{p}}                       

(d) M<(A-Z){{M}_{n}}+Z{{M}_{p}}.

Ans (d)

8.

If  all the atoms of 1 kg of deuterium undergo fusion, approximately how much energy could be released, if the fusion reaction is _{\text{1}}{{\text{H}}^{\text{2}}}+{{\,}_{\text{1}}}{{\text{H}}^{\text{2}}}\to {{\,}_{\text{2}}}\text{H}{{\text{e}}^{\text{3}}}+{{\,}_{\text{0}}}{{\text{n}}^{\text{1}}}+\text{3}\text{.8MeV}

(a)9 × 10¹³ J                                    

(b)9 × 10¹¹ calorie                        

(c)9 × 10¹² kWh                            

(d)9 × 10⁷ kWh.

Ans  (a)

9.

Assuming that about 20 MeV of energy is released per fusion reaction _{\text{1}}{{\text{H}}^{\text{2}}}+{{\,}_{\text{1}}}{{\text{H}}^{\text{2}}}\to {{\,}_{\text{0}}}{{n}^{\text{1}}}+{{\,}_{\text{2}}}\text{H}{{\text{e}}^{\text{3}}} then the mass of ₁H² consumed per day in a fusion reactor of power 1 Megawatt will approximately be

(a) 0.001 gm                                  

(b)0.1 gm

(c) 10.0 gm                                     

(d) 1000 gm.

Ans (b)

10.

Given that mass of proton = 1.00813u, mass of neutron is 1.00894u and mass of
a-particle is 4.00388u, the binding energy of alpha particle is

(a) 28.172 MeV                            

(b) 27.172 MeV                            

(c) 13.52 MeV                               

(d) 56.321 MeV

Ans (a)

11.

Nuclear radius of ₈O¹⁶ is 3 fermi. The nuclear radius of ₈₂Pb²⁰⁵ is

(a) 5.02 fermi                                

(b) 6.02 fermi                                

(c) 7.02 fermi                                

(d) 8.02 fermi

Ans (c)

12.

Let m_p be the mass of a proton, m_n be the mass of a neutron, M₁ be the mass of ₁₀He²⁰ nucleus and M₂ the mass of ₂₀Ca⁴⁰ nucleus. Then

(a) M₂ = 2M₁                                 

(b) M₂> 2M₁                                                    

(c) M₂< 2M₁                                   

(d) M₁< 10 (m_p + m_n)

Ans  (d)

13.

If the nuclear force between two protons, two neutrons and between proton and neutron is denoted by F_pp, F_nn and F_pn respectively then

(a) F_pp = F_np = F_nn                          

(b) F_pp¹F_np but F_pp = F_np                    

(c) F_pp = F_nn¹F_pn                            

(d) F_pp¹F_nn¹F_pn.

Ans (a)

14.

The binding energies per uncleon for a deutron and an a-particle are X₁ and X₂ respectively. What will be the energy Q released in the reaction? _{\text{1}}^{\text{2}}\text{H}+\,_{\text{1}}^{\text{2}}\text{H}\to \,_{\text{2}}^{\text{4}}\text{He}+\text{Q}

(a)  4 (X₂ – X₁)                               

(b) 2 (X₂ – X₁)                                

(c) 4 (X₁ + X₂)                                 

(d) 2 (X₁ + X₂).

Ans (a)

15.

The real mass, M_N of a stable nucleus differs from the total mass of its constituents (protons and neutrons) M_T, in such a way that

(a) M_N>M_T                                                      

(b) M_N is slightly smaller than M_T

(c) M_N = M_T                                                                  

(d) M_N>>M_T.

Ans (b)

16.

If the speed of light were \frac{2}{3} of its present value, the energy released in a given atomic explosion will be decreased by a fraction of

(a) \frac{2}{3}       

(b) \frac{4}{9}       

(c) \frac{5}{9}       

(d) \frac{2}{9}.

Ans (b)

17.

The binding energy per nucleon of deutron and helium atom is 1.1 MeV and 7 MeV respectively. If two deutron atoms react to form a single helium, then the energy released is

(a) 13.9 MeV                                 

(b) 26.9 MeV                                 

(c) 23.6 MeV                                 

(d) 19.2 MeV.

Ans (b)