Alpha Decay

Q. How many alpha and beta particles emit when uranium nucleus
238. 206
​​​​​ U. To. Pb. ?
92. 82

Q.

Choose the correct option in which the ionization power of alpha(α), beta(β) and gamma(γ) particles is arranged correctly.

1. α > β < γ

2. γ < β < α

3. α < β < γ

4. γ > β, and α = 0

Q.

What are baryons and leptons?How are they both conserved?

Q. In an alpha decay, the mass number of an element decreases by:

1. 4
2. 1
3. 2
4. 0

Q. During a negative beta decay,

1. An atomic electron is ejected
2. An electron which is already present within the nucleus is ejected
3. A neutron in the nucleus decays emitting an electron
4. A proton in the nucleus decays emitting an electron

Q.

What Is Lagrangian And Hamiltonian?

Q.

The Radioactivity of an element when it undergoes a chemical change to form a chemical compound

1. Decreases

2. Increases

3. Increases or decreases depending on the radioelement

4. Neither Increases or decreases

Q.

Which of the following radiation is most dangerous because of its high penetrating power and high energy?

1. Alpha particles

2. Beta particles

3. Gamma rays

4. none of these

Q. The above is a plot of binding energy per nucleon $E_b$, against the nuclear mass M; A, B, C, D, E, F correspond to different nuclei. Consider four reactions;
[AIEEE-2009]

(i) A + B → C + E (ii) C → A + B + E
(iii) D + E → F + E (iv) F → D + E + E

Where $\epsilon$ is the energy released? In which reactions is $\epsilon$ positive?

1. (i) and (iv)
2. (ii) and (iv)
3. (ii) and (iii)
4. (i) and (iii)

Q. Why can gamma rays travel through the air for a long distance?

1. They have very high kinetic energy.

2. They have a smaller rate of collision with the atoms (or molecules) of the medium.

3. They possess more mass than an alpha particle.

4. They have less ionizing power but more penetrating power.

Q. Calculate the Q-value in the following decay:
${}_8^{19}O{\to }_9^{19}F+e^{-}+\overline{v}.$
These may look like long calculations; use the unit amu or u for the masses, and $c^2=931\frac{MeV}{u},$ and it will become much simpler.
$Atomicmasses{:}_8^{19}O:19.003576u;{}_9^{19}F:18.998403u.$

1. 2.021 MeV
2. 3.754 MeV
3. 4.816 MeV
4. 5.165 MeV

Q.

The kinetic energy after an alpha decay is mainly carried by the alpha particle.

1. False

2. True

Q.

A radioactive element decays as follows:

_aP^b - 2α → _cQ^d → _eR^f + _-1e⁰

The relation between a, b, e, & f is

1. i) f = d = b-8 and ii) e = c = a -4

2. i) f = d = b-8 and ii) e = c +1 = a -3

3. i) f = d+2 = b-8 and ii) e = c +1 = a -3

4. i) f = d-8 = b and ii) e = c +1 = a -4

5. i) f = d = b-4 and ii) e = c +1 = a -3

Q. Plutonium undergoes $\alpha$-decay to form uranium:
$23994\mathrm{Pu}\to 23592U+42\mathrm{He}$
The atomic masses of the elements are as follows:

• ${\text{m}}_{\text{Pu}}=239.0522\text{a.m.u.}$
• ${\text{m}}_{\text{U}}=235.044\text{a.m.u.}$
• ${\text{m}}_{\text{He}}=4.0026\text{a.m.u.}$

Calculate the kinetic energy imparted to the daughter nuclei due to the mass defect.

1. $6.74\text{MeV}$
2. $5.22\text{MeV}$
3. $10.44\text{MeV}$
4. $2.61\text{MeV}$

Q. Show by equations, the effect on the proton number Z and mass number A of the parent nucleus brought about by the two types of radioactive decay. [5 MARKS]

Q.

Particles which can be added to the nucleus of an atom without changing its chemical properties are called

1. neutrons

2. electrons

3. protons

4. alpha particles

Q. On the bombardment of a neutron with Boron. $\alpha$-particle is emitted and product nuclei formed is

1. ${}_6{C}^{12}$
2. ${}_{3}L{i}^6$
3. ${}_{3}L{i}^7$
4. ${}_{4}B{e}^9$

Q.

Define Gamma rays.

Q. In an alpha decay the mass number of an element decreases by __.

Q. The the system in the figure is in equilibrium. The value of PR in terms of RQ is equal to

1. 
2. 
3. 
4. 

Q. In a radioactive decay chain, the initial nucleus is ${}_{90}^{232}Th$. At the end there are $6\alpha -$ particles and $4\beta -$ particles which are emitted. If the end nucleus, If ${}_Z^{A}X,A$ and $Z$ are given by:

1. $A=208;Z=80$
2. $A=200;Z=81$
3. $A=202;Z=80$
4. $A=208;Z=82$

Q. Which of the following is the approximate energy equivalent of the mass of an $\alpha$ - particle?

1. $2396\text{MeV}$
2. $3755\text{MeV}$
3. $4840\text{MeV}$
4. $1877\text{MeV}$

Q.

Radioactive material A has a decay constant 8λ and material B has decay constant λ. Initially they have same number of nuclei. After what time, the ratio of number of nuclei of material B to that A will be e?

Q. $\alpha$ and $\beta$ - particles emitted when uranium nucleus ${}_{92}{U}^{238}$ decay to ${}_{82}P{b}^{214}$ are

1. 2- $\alpha$ particles and 6 $\beta$ particles
2. 6 - $\alpha$ particles and 2- $\beta$ particles
3. 4 $\alpha$ - particles and 2 $\beta$ particles
4. 2 $\alpha$ -particles and 4 $\beta$-particles

Q. When a nucleus with atomic number Z and mass number A undergoes a radioactive decay process

1. both Z and A will decrease if the process is $\alpha$-decay
2. Z will decrease but A will not change if the process is ${\beta }^{+}$ - decay
3. Z will increase but A will not change, if the process is ${\beta }^{-}$- decay
4. Z and A will remain unchanged if the process is $\gamma$ - decay

Q. The mass number and atomic number of an element are not changed when it emits ______

Q. An element $\text{X}$ disintegrates by $\alpha$-emission and the new element further disintegrates twice by $\beta$-emission and once by $\gamma$-emission. If $\text{Y}$ is the final element formed, then:

1. $\text{X}$ and $\text{Y}$ are isobars.
2. $\text{X}$ and $\text{Y}$ are isotones.
3. $\text{X}$ and $\text{Y}$ are isotopes.
4. None of the above

Q. A nucleus with atomic number Z and neutron number N undergoes two decay processes. The result is a nucleus with atomic number Z-3 and neutron number N-1. Which decay processes took place?

1. Two ${\beta }^{-}$ decays
2. Two ${\beta }^{+}$ decays
3. An $\alpha -decay$ and a ${\beta }^{-}$ decay
4. An $\alpha -decay$ and a ${\beta }^{+}$ decay

Q.

The fundamental particle not present in a hydrogen atom is__________.

Q.

If an aluminum nucleus emit $\gamma$-rays .What is the resulting nucleus?