# 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

Correct Marks 4

Incorrectly Marks -1

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.

Correct Marks 4

Incorrectly Marks -1

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

Incorrectly Marks -1

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

Correct Marks 4

Incorrectly Marks -1

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

Incorrectly Marks -1

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

Correct Marks 4

Incorrectly Marks -1

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

Correct Marks 4

Incorrectly Marks -1

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

Incorrectly Marks -1

Q 8.

Positrons

B

neutrons

C

protons

D

electrons

##### Explanation

Correct Marks 4

Incorrectly Marks -1

Q 9.

B

C

D

##### Explanation

Correct Marks 4

Incorrectly Marks -1

Q 10.

A

B

D