# JEE Main

Explore popular questions from Nuclear Chemistry for JEE Main. This collection covers Nuclear Chemistry previous year JEE Main questions hand picked by experienced teachers.

## Mathematics

Nuclear Chemistry

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Q 1. If the atomic masses of Lithium, Helium and Proton are 7.01823 amu, 4.00387 amu and 1.00815 amu respectively, calculate the energy that will be evolved in the reaction. .
(Given that 1 amu = 931 MeV)

17.3 MeV

B

17.8 MeV

C

17.2 MeV

D

17.0 MeV

##### Explanation

Total mass of the reacting species and The mass of the resulting species amu
Mass of reacting species converted into energy, i.e., amu
Energy evolved in the reaction MeV.

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Q 2. Calculate the mass defect and binding energy per nucleon for . [The mass of , mass of hydrogen atom = 1.008142 amu and mass of neutron = 1.008982 amu].

8.77 MeV

B

8.25 MeV

C

9.01 MeV

D

8.00 MeV

##### Explanation

Number of protons in Number of neutrons = 59 - 27 = 32 The binding energy per nucleon Correct Marks 4

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Q 3. Calculate the number of neutrons in the remaining atom after emission of an alpha particle from atom

A

146

B

145

144

D

143

##### Explanation

On account of emission of an alpha particle, the atomic mass is decreased by 4 units and atomic number by 2 units
So, Atomic mass of daughter element = 234
Atomic number of daughter element = 90
Number of neutrons = Atomic mass - Atomic number
= 234 - 90 = 144

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Q 4. Radioactive disintegration of takes place in the following manner into  , Determine mass number and atomic number of RaC.

A

214 and 84

B

214 and 86

214 and 83

D

214 and 85

##### Explanation

Parent element is Atomic mass = 226
Atomic number = 88
RaC is formed after the emission of 3 alpha particles. Mass of 3 alpha particles So Atomic mass of RaC With emission of one α-particle, atomic number is decreased by 2 and with emission of β-particle, atomic number is increased by 1.
So Atomic number of RaC Correct Marks 4

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Q 5. How many 'α and β' particles will be emitted when changes into A

2 and 6

4 and 2

C

2 and 4

D

6 and 2

##### Explanation

The change is; Decrease in mass Mass of 1 α-particle Therefore, number of α-particles emitted Number of β-particles emitted  Hence number of α-particles = 4 and number of β-particles = 2

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Q 6. The isotopes and occur in nature in the ratio of 140 : 1. Assuming that at the time of earth formation, they were present in equal ratio, make an estimation of the age of earth. The half life period of and are and years respectively years

B years

C years

D years

##### Explanation

Let the age of the earth be t years
For  ......(i)
For  ......(ii) Subtracting eq. (ii) from eq. (i)     years

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Q 7. The value of amu is which of the following?

A

1.57 × 10-24 kg

B

1.66 × 10-24 kg

C

1.99 × 10-23 kg

1.66 × 10-27 kg

##### Explanation Correct Marks 4

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Q 8. Positrons

B

neutrons

C

protons

D

electrons

##### Explanation Correct Marks 4

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Q 9.  B C D ##### Explanation Correct Marks 4

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Q 10. A B  D ##### Explanation 