Physics · Chemistry

Radioactivity and Nuclear Physics

519 Questions

Radioactivity and nuclear physics encompass the study of radioactive decay processes, neutron to proton ratios, and nuclear medicine. Questions cover various detection mechanisms, including scintillation counters and neutrino telescopes. These concepts are frequently tested in advanced science and civil services examinations.

Radioactive decayNuclear medicineParticle detectionNeutrino telescopesCosmic ray detection

Radioactivity and Nuclear Physics Questions

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

A radioactive element ${X} _{90}^{238}$ decays into ${Y} _{83}^{222}$. The number of $\beta$-particles emitted are

  1. 1

  2. 2

  3. 4

  4. 6
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The radioactive element undergoes four alpha decays and one beta decay as follows:


$^{238} _{90}X\rightarrow ^{222} _{83}Y+4^4 _2He+ ^{0} _{-1}e$

Clearly only one beta particle (electron) is emitted.

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

For which of the following events will the resulting products have more mass than the mass of the stuff from which the products came?

  1. Alpha decay

  2. Beta decay

  3. An exothermic nuclear reaction

  4. An endothermic nuclear reaction
  5. Nuclear fission of uranium $-235$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In an endothermic nuclear reaction, heat energy is given to the reaction to proceed and thus according to Einstein's mass-energy equivalence law, heat energy given gets converted into additional mass which results in the formation of products with more mass than the reactants.

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

A radioactive substance contains a number of identical nuclei that emit $\beta$- particles. Which property of these nuclei remains unaltered by emission?

  1. charge

  2. neutron number

  3. nucleon number

  4. proton number
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

We know that in any $\beta -$ emission the mass number of the nucleus does not changes .

This implies that the nucleon number will remain same. 
So, option C is correct.

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

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

  1. $ _{93}Np^{238}$
  2. $ _{94}Pu^{239}$
  3. $ _{94}Pu^{238}$
  4. $ _{92}U^{238}$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A (d, 2n) reaction on U-238 (Z=92, A=238) involves adding a deuteron (Z=1, A=2) and removing two neutrons (Z=0, A=1 each), resulting in Z=93, A=238 (Np-238). A subsequent beta decay (Z increases by 1, A stays same) results in Z=94, A=238, which is Pu-238.

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

The electron emitted in beta radiation originates from

  1. inner orbits of atoms

  2. free electrons existing in nuclei

  3. decay of a neutron in a nucleus

  4. photon escaping from the nucleus
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The electron emitted in beta radiation may originates from neutron and it increases the atomic number $1$.

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

In radioactive decay process, the emitted negatively charged $\beta$ - particles are :

  1. the electrons present inside the nucleus

  2. the electrons produced as a result of the decay of neutrons inside the nucleus

  3. the electrons produced as a result of collisions between atoms

  4. the electrons orbiting around the nucleus
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Beta decay can involve the emission of either electrons or positrons. The electrons or positrons emitted in a $\beta$ - decay do not exist inside the nucleus. They are only created at the time of emission, just as photons are created when an atom makes a transition from higher to a lower energy state.
In negative $\beta$- decay a neutron in the nucleus is transformed into a proton, an electron and an antineutrino. Hence, in radioactive decay process, the negatively charged emitted $\beta$- particles are the electrons produced as a result of the decay of neutrons present inside the nucleus.

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

The number of neutrons decreases by 1 after radioactive decay. Identify the type of decay.

  1. Alpha decay
  2. ${\beta}^{-}$ decay
  3. ${\beta}^{+}$ decay

  4. Electron capture

  5. Gamma decay
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

We know that for $\beta^-$ decay, one neutron is converted into proton and electron and the electron is ejected in the reaction. For this, the number of neutrons will decrease by one unit. 

But in $\beta^+$  decay , the positron is ejected and neutron number will increase by one unit. 

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

Find out the product of a $Co^{60}$ atom that undergoes one beta plus decays?

  1. iron-60

  2. manganese-60

  3. copper-60

  4. copper-62

  5. iron-62
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$\beta^+$ decay: $^{60} _{28}Co \rightarrow$ $^{A} _{Z}X$ $+$ $^0 _{+1}e$ 

In a nuclear reaction, the mass number as well as the atomic number is conserved.
$\therefore$  $60 = 0 + A$ $\implies A =60$
Also, $27 = 1 + Z$  $\implies Z = 26$
Thus, the product of the reaction is iron-60  i.e $^{60} _{26}Fe$.

Multiple choice group 17 elements - trends in chemical properties group 17 elements - properties p- block elements-ii p-block elements chemistry

In very recent Sunami in Japan, food materials were banned as they were contaminated with radioactivity . Which of the following was found to have radioactive beyond prescribed limit ?

  1. F

  2. Cl

  3. I

  4. At
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Tokyo, the city first reported a spike of radioactive iodine in its water supply on March 23, 2011 at levels below the limit for adults but above the threshold of safety for infants; since then, iodine levels in Tokyo's water have declined below both thresholds. 


Above-limit levels of radioactive iodine and cesium have also been found in milk and vegetables in seven prefectures in Japan. 

Hence,option C is correct.


Multiple choice physics motion and measurement physical quantities units - definitions and systems physical quantities like mass and weight

The 'rad' is the correct unit used to report the measurement of

  1. the rate of decay of radioactive source

  2. the ability of a beam of gamma ray photons to produce ions in a target

  3. the energy delivered by radiation to a target

  4. the biological effect of radiation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Rad is the unit of absorbed dose of ionizing radiation. One rad is equal approximately to the absorbed dose delivered when soft tissue is exposed to one-roentgen of medium-voltage radiation. Thus this is the bilogical effect of radiation.

Multiple choice chemistry energy : forms and sources renewable and non-renewable resources renewable and non-renewable sources of energy production of electricity from solar energy

Compared to the one used on Hiroshima, the Nagasaki bomb was rounder and fatter, so it was called "Fat Man." The fissile material was 

  1. plutonium 239

  2. plutonium 237

  3. uranium 235

  4. uranium 239
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Plutonium 239

Fat man was an implosive type nuclear weapon with solid plutonium core.