Tag: nuclear structure

Questions Related to nuclear structure

If mass-energy equvalence is taken into account, when water is cooled to form ice, the mass of ater should

nuclear reactions nuclear structure nuclei atomic nuclei physics

  1. Increase

  2. Remain unchanged

  3. decrease

  4. First increase and then decrease

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Correct Option: C
Explanation:

As we know that when water is converted into ice then it releases 

energy to the atmosphere, in other words, it can be said that
 it releases some mass to the atmosphere because mass and 
energy are equivalent. 
So option C is correct that mass will decrease.

Two light nuclei of masses $m _1$ and $m _2 $ are fused to form a more stable nucleus of mass $m _3$ then :-

nuclear reactions nuclear structure nuclei atomic nuclei physics

  1. $m _3 = | m _1 - m _2 | $

  2. $m _3 < ( m _1 + m _2 ) $

  3. $m _3 > ( m _1 - m _2 ) $

  4. $m _3 = | m _1 + m _2 | $

Show answer
Correct Option: B
Explanation:

When two nuclei of masses ${m _1}$ and ${m _2}$ are fused to form a stable nucleus of mass ${m _3}$ and some of the mass is converted in energy.

Therefore,

${m _3} < {m _1} + {m _2}$

A photon of $1.7 \times 10 ^{-13}$ joule is absorbed by a material under special circumstances. The correct statement is :

nuclear reactions nuclear structure nuclei atomic nuclei physics

  1. Electron of the atoms of absorbed material will go the higher energy states.

  2. Electron and positron pair will be created

  3. Only positron pair will be produced

  4. Photoelectric effect will occur and electron will be produced

Show answer
Correct Option: B
Explanation:

For electron and positron pair production, minimum energy is $1.02\ MeV$.
Energy of photon is given: $ 1.7 \times 10^{-3} J=\dfrac{1.7 \times 10^{-13}}{1.6 \times 10^{-19}}$$=1.06 \, MeV$.
Since energy of photon is greater than 1.02 MeV, electron positron pair will be created.