1 both the neutron number and the proton number change
2 there is no change in the proton number and the neutron number
3 only the neutron number changes
4 only the proton number changes
Explanation:
B There is no change in the proton number and the neutrons number as the emission takes place as a result of excitation or de - excitation of nuclei because $\gamma$-rays have no charge or mass.
JCECE-2008
NUCLEAR PHYSICS
147651
Which one of the following is the unit of activity of a radioactive source?
1 Lux
2 Becquerel
3 Tesla
4 Siemens
Explanation:
B Unit of activity of radioactive source is expressed in the SI system of units by Becquerel which is exactly equal to one disintegration per second. Becquerel is a very small amount of radioactivity.
NDA (II) 2008
NUCLEAR PHYSICS
147723
Which one of the following is a possible nuclear reaction?
C In any nuclear reaction mass number and atomic number should remain conserved. Reaction (c) satisfies this condition. Also for ${ }_{93}^{239} \mathrm{~Np}$, neutron to photon ratio is greater than 1.52 , which makes it unstable.
BCECE-2008
NUCLEAR PHYSICS
147652
A nucleus ${ }_{\mathrm{Z}}^{\mathrm{A} X} \mathrm{X}$ emits one $\alpha$ and $2 \beta$ particles, then final nucleus is :
1 $\mathrm{Y}_{\mathrm{Z}-2}^{\mathrm{A}}$
2 $\mathrm{Y}_{\mathrm{Z}-4}^{\mathrm{A}-4}$
3 $\mathrm{Y}_{\mathrm{Z}}^{\mathrm{A}-4}$
4 $X_{Z}^{A}$
Explanation:
C A nucleus ${ }_{Z}^{\mathrm{A}} \mathrm{X}$ emits one $\alpha$ and $2 \beta$ particles, then final nucleus is $\mathrm{Z}^{\mathrm{A}} \stackrel{\alpha}{\longrightarrow} \mathrm{z}-2 \mathrm{X}^{\mathrm{A}-4} \stackrel{+2 \mathrm{~B}}{\longrightarrow} \mathrm{z-2+2} \mathrm{Y}^{\mathrm{A}-4}$ or ${ }_{\mathrm{Z}} \mathrm{Y}^{\mathrm{A}-4}$
1 both the neutron number and the proton number change
2 there is no change in the proton number and the neutron number
3 only the neutron number changes
4 only the proton number changes
Explanation:
B There is no change in the proton number and the neutrons number as the emission takes place as a result of excitation or de - excitation of nuclei because $\gamma$-rays have no charge or mass.
JCECE-2008
NUCLEAR PHYSICS
147651
Which one of the following is the unit of activity of a radioactive source?
1 Lux
2 Becquerel
3 Tesla
4 Siemens
Explanation:
B Unit of activity of radioactive source is expressed in the SI system of units by Becquerel which is exactly equal to one disintegration per second. Becquerel is a very small amount of radioactivity.
NDA (II) 2008
NUCLEAR PHYSICS
147723
Which one of the following is a possible nuclear reaction?
C In any nuclear reaction mass number and atomic number should remain conserved. Reaction (c) satisfies this condition. Also for ${ }_{93}^{239} \mathrm{~Np}$, neutron to photon ratio is greater than 1.52 , which makes it unstable.
BCECE-2008
NUCLEAR PHYSICS
147652
A nucleus ${ }_{\mathrm{Z}}^{\mathrm{A} X} \mathrm{X}$ emits one $\alpha$ and $2 \beta$ particles, then final nucleus is :
1 $\mathrm{Y}_{\mathrm{Z}-2}^{\mathrm{A}}$
2 $\mathrm{Y}_{\mathrm{Z}-4}^{\mathrm{A}-4}$
3 $\mathrm{Y}_{\mathrm{Z}}^{\mathrm{A}-4}$
4 $X_{Z}^{A}$
Explanation:
C A nucleus ${ }_{Z}^{\mathrm{A}} \mathrm{X}$ emits one $\alpha$ and $2 \beta$ particles, then final nucleus is $\mathrm{Z}^{\mathrm{A}} \stackrel{\alpha}{\longrightarrow} \mathrm{z}-2 \mathrm{X}^{\mathrm{A}-4} \stackrel{+2 \mathrm{~B}}{\longrightarrow} \mathrm{z-2+2} \mathrm{Y}^{\mathrm{A}-4}$ or ${ }_{\mathrm{Z}} \mathrm{Y}^{\mathrm{A}-4}$
1 both the neutron number and the proton number change
2 there is no change in the proton number and the neutron number
3 only the neutron number changes
4 only the proton number changes
Explanation:
B There is no change in the proton number and the neutrons number as the emission takes place as a result of excitation or de - excitation of nuclei because $\gamma$-rays have no charge or mass.
JCECE-2008
NUCLEAR PHYSICS
147651
Which one of the following is the unit of activity of a radioactive source?
1 Lux
2 Becquerel
3 Tesla
4 Siemens
Explanation:
B Unit of activity of radioactive source is expressed in the SI system of units by Becquerel which is exactly equal to one disintegration per second. Becquerel is a very small amount of radioactivity.
NDA (II) 2008
NUCLEAR PHYSICS
147723
Which one of the following is a possible nuclear reaction?
C In any nuclear reaction mass number and atomic number should remain conserved. Reaction (c) satisfies this condition. Also for ${ }_{93}^{239} \mathrm{~Np}$, neutron to photon ratio is greater than 1.52 , which makes it unstable.
BCECE-2008
NUCLEAR PHYSICS
147652
A nucleus ${ }_{\mathrm{Z}}^{\mathrm{A} X} \mathrm{X}$ emits one $\alpha$ and $2 \beta$ particles, then final nucleus is :
1 $\mathrm{Y}_{\mathrm{Z}-2}^{\mathrm{A}}$
2 $\mathrm{Y}_{\mathrm{Z}-4}^{\mathrm{A}-4}$
3 $\mathrm{Y}_{\mathrm{Z}}^{\mathrm{A}-4}$
4 $X_{Z}^{A}$
Explanation:
C A nucleus ${ }_{Z}^{\mathrm{A}} \mathrm{X}$ emits one $\alpha$ and $2 \beta$ particles, then final nucleus is $\mathrm{Z}^{\mathrm{A}} \stackrel{\alpha}{\longrightarrow} \mathrm{z}-2 \mathrm{X}^{\mathrm{A}-4} \stackrel{+2 \mathrm{~B}}{\longrightarrow} \mathrm{z-2+2} \mathrm{Y}^{\mathrm{A}-4}$ or ${ }_{\mathrm{Z}} \mathrm{Y}^{\mathrm{A}-4}$
1 both the neutron number and the proton number change
2 there is no change in the proton number and the neutron number
3 only the neutron number changes
4 only the proton number changes
Explanation:
B There is no change in the proton number and the neutrons number as the emission takes place as a result of excitation or de - excitation of nuclei because $\gamma$-rays have no charge or mass.
JCECE-2008
NUCLEAR PHYSICS
147651
Which one of the following is the unit of activity of a radioactive source?
1 Lux
2 Becquerel
3 Tesla
4 Siemens
Explanation:
B Unit of activity of radioactive source is expressed in the SI system of units by Becquerel which is exactly equal to one disintegration per second. Becquerel is a very small amount of radioactivity.
NDA (II) 2008
NUCLEAR PHYSICS
147723
Which one of the following is a possible nuclear reaction?
C In any nuclear reaction mass number and atomic number should remain conserved. Reaction (c) satisfies this condition. Also for ${ }_{93}^{239} \mathrm{~Np}$, neutron to photon ratio is greater than 1.52 , which makes it unstable.
BCECE-2008
NUCLEAR PHYSICS
147652
A nucleus ${ }_{\mathrm{Z}}^{\mathrm{A} X} \mathrm{X}$ emits one $\alpha$ and $2 \beta$ particles, then final nucleus is :
1 $\mathrm{Y}_{\mathrm{Z}-2}^{\mathrm{A}}$
2 $\mathrm{Y}_{\mathrm{Z}-4}^{\mathrm{A}-4}$
3 $\mathrm{Y}_{\mathrm{Z}}^{\mathrm{A}-4}$
4 $X_{Z}^{A}$
Explanation:
C A nucleus ${ }_{Z}^{\mathrm{A}} \mathrm{X}$ emits one $\alpha$ and $2 \beta$ particles, then final nucleus is $\mathrm{Z}^{\mathrm{A}} \stackrel{\alpha}{\longrightarrow} \mathrm{z}-2 \mathrm{X}^{\mathrm{A}-4} \stackrel{+2 \mathrm{~B}}{\longrightarrow} \mathrm{z-2+2} \mathrm{Y}^{\mathrm{A}-4}$ or ${ }_{\mathrm{Z}} \mathrm{Y}^{\mathrm{A}-4}$
