Tag: nuclei

Questions Related to nuclei

A positron is emitted by radioactive nucleus of proton number $90$. The product nucleus will have proton number :

physics nuclei beta decay change in nucleus due to radioactive decay alpha, beta and gamma particles (rays) and their properties

  1. $91$

  2. $90$

  3. $89$

  4. $88$

Show answer
Correct Option: C
Explanation:

The given nuclear reaction is-

$ _{90}X \rightarrow   _{+1}e $  $+ $ $ _zY$ 
Using law of conservation of atomic (or proton) number:
$90 = 1 + Z$
$\implies$ $Z = 89$
Thus the product nucleus will have proton number $89$.

When $ _{15}P^{30}$ decays to become  $ _{14}Si^{30}$, which particle is released ?

physics nuclei beta decay change in nucleus due to radioactive decay alpha, beta and gamma particles (rays) and their properties

  1. electron

  2. $\alpha$-particle

  3. neutron

  4. positron

Show answer
Correct Option: D
Explanation:

The nuclear reaction :   $ _{15}P^{30}\rightarrow$   ${14}Si^{30} + $  $ _{+1}e^0$

Thus a positron is emitted during the decay of  $ _{15}P^{30}$ into   $ _{14}Si^{30}$.

A nucleus $ _{  }^{ 220 }{ X }$ at rest decays emitting an $\alpha$- particle. If energy of daughter nucleus is $0.2MeV$, $Q$ value of the reaction is

physics nuclei beta decay change in nucleus due to radioactive decay alpha, beta and gamma particles (rays) and their properties

  1. $10.8MeV$

  2. $10.9MeV$

  3. $11MeV$

  4. $11.1MeV$

Show answer
Correct Option: A

The antiparticle of electron is

physics nuclei beta decay change in nucleus due to radioactive decay alpha, beta and gamma particles (rays) and their properties

  1. positron

  2. $\alpha $-particle

  3. proton

  4. $\beta $-particle

Show answer
Correct Option: A
Explanation:

Antiparticle of electron $ _{ -1 }{ e }^{ 0 }$ is positron $ _{ +1 }{ e }^{ 0 }$

Which word equation represents $\beta^+$ decay?

physics nuclei beta decay change in nucleus due to radioactive decay alpha, beta and gamma particles (rays) and their properties

  1. Proton $\rightarrow$ neutron $+$ electron $+$ electron antineutrino

  2. Proton $\rightarrow$ neutron $+$ electron $+$ electron neutrino

  3. Proton $\rightarrow$ neutron $+$ positron $+$ electron antineutrino

  4. Proton $\rightarrow$ neutron $+$ positron $+$ electron neutrino

Show answer
Correct Option: D
Explanation:

 Positive beta decay $(β+\ \ \text{decay})$ also called the  positron emission. In this decay  a proton in the parent nucleus decays into a neutron that remains in the daughter nucleus, and the nucleus emits a neutrino and a positron, which is a positive particle like an ordinary electron in mass but of opposite charge. Thus, positive beta decay produces a daughter nucleus, the atomic number of which is one less than its parent and the mass number of which is the same.

The equation can be written as :

$p \rightarrow n+ e^+ + v _e$

The number of $\beta$-particles, if a radioactive element $ _{90}X^{238}$ decays into $ _{83}Y^{222}$ is :

physics nuclei beta decay change in nucleus due to radioactive decay alpha, beta and gamma particles (rays) and their properties

  1. $4$

  2. $6$

  3. $2$

  4. $1$

Show answer
Correct Option: D

Which of the following nuclei is produced when a $ _{92}U^{238}$ nucleus undergoes a $(d, 2n)$ reaction followed by a beta decay?

physics nuclei beta decay change in nucleus due to radioactive decay alpha, beta and gamma particles (rays) and their properties

  1. $ _{93}Np^{238}$

  2. $ _{94}Pu^{239}$

  3. $ _{94}Pu^{238}$

  4. $ _{92}U^{238}$

Show answer
Correct Option: C

Which of the following relations is correct?

nuclear reactions nuclear structure nuclei atomic nuclei physics

  1. $E = mc$

  2. $E = mc^2$

  3. $E = 2mc^2$

  4. $E = mc^2/4$

Show answer
Correct Option: B
Explanation:

According to Einstein, energy and mass are related by the relation.
$E = mc^2$
where c is the speed of light in vacuum.

One milligram of matter is converted into energy. The energy released will be

nuclear reactions nuclear structure nuclei atomic nuclei physics

  1. $9\times 10^{6} J$

  2. $9\times 10^{8}J$

  3. $9\times 10^{10}J$

  4. $9\times 10^{12}J$

Show answer
Correct Option: C
Explanation:

Here, $m = 1\ mg = 1\times 10^{-3} g $

             $= 1\times 10^{-6}kg$
According to Einstein mass-energy equivalence
                $E = mc^{2}$
where $c$ is the speed of light in vacuum
$\therefore E = (1\times 10^{-6} kg)(3\times 10^{8}ms^{-1})^{2}$
$ = 9\times 10^{10}J$.

The relation between the volume $V$ and the mass $M$ of a nucleus is:

nuclear reactions nuclear structure nuclei atomic nuclei physics

  1. $V\propto M^{3}$

  2. $V\propto M^{1/3}$

  3. $V\propto M$

  4. $V\propto 1/M$

Show answer
Correct Option: C
Explanation:

Since the density of nucleus is fixed.

$D=\cfrac { M }{ V } \ \Rightarrow M=DV\ M\propto V$