Comprehensive Solved Problems in Nuclear Physics for Class 10 Science

Solved problem - Nuclear Physics | Science

Solved problem 6.1

Identify A, B, C, and D from the following nuclear reactions.

Solution:

A is alpha particle, B is neutron, C is proton, and D is electron.

Solved problem 6.2

A radon specimen emits radiation of \(3.7 \times 10^3\) GBq per second. Convert this disintegration in terms of curie. (one curie = \(3.7 \times 10^{10}\) disintegration per second)

Solution:

1 Bq = one disintegration per second one curie = \(3.7 \times 10^{10}\) Bq

$$ \text{Given radiation} = 3.7 \times 10^3 \text{ GBq} $$ $$ = 3.7 \times 10^3 \times 10^9 \text{ Bq} $$ $$ = 3.7 \times 10^{12} \text{ Bq} $$ $$ \text{Since 1 curie} = 3.7 \times 10^{10} \text{ Bq} $$ $$ \text{Therefore, radiation in curie} = \frac{3.7 \times 10^{12}}{3.7 \times 10^{10}} $$ $$ = 100 \text{ curie} $$

Solved problem 6.3

\(^{235}_{92}U\) experiences one \(\alpha -\)decay and one \(\beta -\) decay. Find number of neutrons in the final daughter nucleus that is formed.

Solution:

Let X and Y be the resulting nucleus after the emission of the alpha and beta particles respectively.

$$ ^{235}_{92}U \xrightarrow{\alpha \text{-decay}} ^{231}_{90}X + ^{4}_{2}He $$ $$ ^{231}_{90}X \xrightarrow{\beta \text{-decay}} ^{231}_{91}Y + e^{-} $$

Number of neutrons = Mass number – Atomic number = 231 – 91 = 140

Solved problem 6.4

Calculate the amount of energy released when a radioactive substance undergoes fusion and results in a mass defect of 2 kg.

Solution:

Mass defect in the reaction (m) = 2 kg

Velocity of light (c) = \(3 \times 10^8 \text{ m s}^{-1}\)

By Einstein’s equation,

$$ E = mc^2 $$

So E = \(2 \times (3 \times 10^8)^2\)

= \(1.8 \times 10^{17}\) J