147645
$\beta$-decay means emission of electron from
1 innermost electron orbit
2 a stable nucleus
3 outermost electron orbit
4 radioactive nucleus
Explanation:
D $\beta$-decay- Radioactive decay in which an electron is emitted. Ex- $\beta^{-}$decay $-{ }_{15}^{32} \mathrm{P} \rightarrow{ }_{16}^{32} \mathrm{~S}+{ }_{-1} \mathrm{e}_{\text {electron }}^{0}$ $\beta^{+}$decay $-{ }_{11}^{22} \mathrm{Na} \rightarrow{ }_{10}^{22} \mathrm{Ne}+\mathrm{e}_{\text {positron }}^{+}$ $\beta$-decay is the emission of electron from the radioactive nucleus.
Manipal UGET-2009
NUCLEAR PHYSICS
147658
In the uranium radioactive series, the initial nucleus is ${ }_{92} \mathrm{U}^{238}$ and the final nucleus is ${ }_{82} \mathrm{~Pb}^{206}$. When the uranium nucleus decays to lead, the number of $\alpha$-particles emitted will be
1 1
2 2
3 3
4 8
Explanation:
D In alpha decay, mass number A and atomic number $Z$ reducing by 4 and 2 respectively. In $\beta$-decay, mass number unchanged but atomic number increasing by 1 . The number of $\alpha$-particles emitted $=\frac{238-206}{4}=8$
CG PET- 2004
NUCLEAR PHYSICS
147661
Consider the following statements:
1 1,2 and 4 only
2 2,3 and 4 only
3 3 only
4 1,2, 3 and 4
Explanation:
C In $\beta^{+}$decay or positron emission the weak interaction converts an atomic nucleus into a nucleus with atomic number decreased by one while emitting a positron $\left(\mathrm{e}^{+}\right)$and an electron neutrino $\left(\mathrm{v}_{\mathrm{e}}\right) \cdot \beta^{+}$decay generally occurs in proton-rich nuclei. The equation - ${ }_{\mathrm{z}} \mathrm{X}^{\mathrm{A}} \rightarrow{ }_{\mathrm{z}-1} \mathrm{X}^{\mathrm{A}}+\mathrm{e}^{+}+\mathrm{v}_{\mathrm{e}}$
SCRA-2015
NUCLEAR PHYSICS
147666
A fraction $f_{1}$ of a radioactive sample decays in one mean life and a fraction $f_{2}$ decay is one half-life
1 $f_{1}>f_{2}$
2 $\mathrm{f}_{1} \lt \mathrm{f}_{2}$
3 $\mathrm{f}_{1}=\mathrm{f}_{2}$
4 may be (a), (b) or (c) depending on the values of the mean life and half-life
Explanation:
A Fraction decayed in one mean life must be bigger than the fraction decayed in one half life. Mean life $(\tau)=\frac{1}{\lambda}$ Half life $\left(\mathrm{T}_{1 / 2}\right)=\frac{\ln 2}{\lambda}=\frac{0.693}{\lambda}$ So, $\tau>\mathrm{T}_{1 / 2}$ Therefore greater fraction will decay in longer time Or $f_{1}>f_{2}$
UPSEE - 2012
NUCLEAR PHYSICS
147672
In the reaction given below ${ }_{86} \mathrm{~A}^{222} \rightarrow{ }_{84} \mathrm{~B}^{210}$ how many $\alpha$ and $\beta$-particles are emitted?
1 $6 \alpha, 3 \beta$
2 $3 \alpha, 4 \beta$
3 $4 \alpha, 3 \beta$
4 $3 \alpha, 6 \beta$
Explanation:
B The given reaction ${ }_{86} \mathrm{~A}^{222} \stackrel{-3 \alpha}{\longrightarrow}{ }_{80} \mathrm{~B}^{210} \stackrel{4 \beta}{\longrightarrow}{ }_{84} \mathrm{C}^{210}$ So, $3 \alpha$ and $4 \beta$ particle are emitted.
147645
$\beta$-decay means emission of electron from
1 innermost electron orbit
2 a stable nucleus
3 outermost electron orbit
4 radioactive nucleus
Explanation:
D $\beta$-decay- Radioactive decay in which an electron is emitted. Ex- $\beta^{-}$decay $-{ }_{15}^{32} \mathrm{P} \rightarrow{ }_{16}^{32} \mathrm{~S}+{ }_{-1} \mathrm{e}_{\text {electron }}^{0}$ $\beta^{+}$decay $-{ }_{11}^{22} \mathrm{Na} \rightarrow{ }_{10}^{22} \mathrm{Ne}+\mathrm{e}_{\text {positron }}^{+}$ $\beta$-decay is the emission of electron from the radioactive nucleus.
Manipal UGET-2009
NUCLEAR PHYSICS
147658
In the uranium radioactive series, the initial nucleus is ${ }_{92} \mathrm{U}^{238}$ and the final nucleus is ${ }_{82} \mathrm{~Pb}^{206}$. When the uranium nucleus decays to lead, the number of $\alpha$-particles emitted will be
1 1
2 2
3 3
4 8
Explanation:
D In alpha decay, mass number A and atomic number $Z$ reducing by 4 and 2 respectively. In $\beta$-decay, mass number unchanged but atomic number increasing by 1 . The number of $\alpha$-particles emitted $=\frac{238-206}{4}=8$
CG PET- 2004
NUCLEAR PHYSICS
147661
Consider the following statements:
1 1,2 and 4 only
2 2,3 and 4 only
3 3 only
4 1,2, 3 and 4
Explanation:
C In $\beta^{+}$decay or positron emission the weak interaction converts an atomic nucleus into a nucleus with atomic number decreased by one while emitting a positron $\left(\mathrm{e}^{+}\right)$and an electron neutrino $\left(\mathrm{v}_{\mathrm{e}}\right) \cdot \beta^{+}$decay generally occurs in proton-rich nuclei. The equation - ${ }_{\mathrm{z}} \mathrm{X}^{\mathrm{A}} \rightarrow{ }_{\mathrm{z}-1} \mathrm{X}^{\mathrm{A}}+\mathrm{e}^{+}+\mathrm{v}_{\mathrm{e}}$
SCRA-2015
NUCLEAR PHYSICS
147666
A fraction $f_{1}$ of a radioactive sample decays in one mean life and a fraction $f_{2}$ decay is one half-life
1 $f_{1}>f_{2}$
2 $\mathrm{f}_{1} \lt \mathrm{f}_{2}$
3 $\mathrm{f}_{1}=\mathrm{f}_{2}$
4 may be (a), (b) or (c) depending on the values of the mean life and half-life
Explanation:
A Fraction decayed in one mean life must be bigger than the fraction decayed in one half life. Mean life $(\tau)=\frac{1}{\lambda}$ Half life $\left(\mathrm{T}_{1 / 2}\right)=\frac{\ln 2}{\lambda}=\frac{0.693}{\lambda}$ So, $\tau>\mathrm{T}_{1 / 2}$ Therefore greater fraction will decay in longer time Or $f_{1}>f_{2}$
UPSEE - 2012
NUCLEAR PHYSICS
147672
In the reaction given below ${ }_{86} \mathrm{~A}^{222} \rightarrow{ }_{84} \mathrm{~B}^{210}$ how many $\alpha$ and $\beta$-particles are emitted?
1 $6 \alpha, 3 \beta$
2 $3 \alpha, 4 \beta$
3 $4 \alpha, 3 \beta$
4 $3 \alpha, 6 \beta$
Explanation:
B The given reaction ${ }_{86} \mathrm{~A}^{222} \stackrel{-3 \alpha}{\longrightarrow}{ }_{80} \mathrm{~B}^{210} \stackrel{4 \beta}{\longrightarrow}{ }_{84} \mathrm{C}^{210}$ So, $3 \alpha$ and $4 \beta$ particle are emitted.
147645
$\beta$-decay means emission of electron from
1 innermost electron orbit
2 a stable nucleus
3 outermost electron orbit
4 radioactive nucleus
Explanation:
D $\beta$-decay- Radioactive decay in which an electron is emitted. Ex- $\beta^{-}$decay $-{ }_{15}^{32} \mathrm{P} \rightarrow{ }_{16}^{32} \mathrm{~S}+{ }_{-1} \mathrm{e}_{\text {electron }}^{0}$ $\beta^{+}$decay $-{ }_{11}^{22} \mathrm{Na} \rightarrow{ }_{10}^{22} \mathrm{Ne}+\mathrm{e}_{\text {positron }}^{+}$ $\beta$-decay is the emission of electron from the radioactive nucleus.
Manipal UGET-2009
NUCLEAR PHYSICS
147658
In the uranium radioactive series, the initial nucleus is ${ }_{92} \mathrm{U}^{238}$ and the final nucleus is ${ }_{82} \mathrm{~Pb}^{206}$. When the uranium nucleus decays to lead, the number of $\alpha$-particles emitted will be
1 1
2 2
3 3
4 8
Explanation:
D In alpha decay, mass number A and atomic number $Z$ reducing by 4 and 2 respectively. In $\beta$-decay, mass number unchanged but atomic number increasing by 1 . The number of $\alpha$-particles emitted $=\frac{238-206}{4}=8$
CG PET- 2004
NUCLEAR PHYSICS
147661
Consider the following statements:
1 1,2 and 4 only
2 2,3 and 4 only
3 3 only
4 1,2, 3 and 4
Explanation:
C In $\beta^{+}$decay or positron emission the weak interaction converts an atomic nucleus into a nucleus with atomic number decreased by one while emitting a positron $\left(\mathrm{e}^{+}\right)$and an electron neutrino $\left(\mathrm{v}_{\mathrm{e}}\right) \cdot \beta^{+}$decay generally occurs in proton-rich nuclei. The equation - ${ }_{\mathrm{z}} \mathrm{X}^{\mathrm{A}} \rightarrow{ }_{\mathrm{z}-1} \mathrm{X}^{\mathrm{A}}+\mathrm{e}^{+}+\mathrm{v}_{\mathrm{e}}$
SCRA-2015
NUCLEAR PHYSICS
147666
A fraction $f_{1}$ of a radioactive sample decays in one mean life and a fraction $f_{2}$ decay is one half-life
1 $f_{1}>f_{2}$
2 $\mathrm{f}_{1} \lt \mathrm{f}_{2}$
3 $\mathrm{f}_{1}=\mathrm{f}_{2}$
4 may be (a), (b) or (c) depending on the values of the mean life and half-life
Explanation:
A Fraction decayed in one mean life must be bigger than the fraction decayed in one half life. Mean life $(\tau)=\frac{1}{\lambda}$ Half life $\left(\mathrm{T}_{1 / 2}\right)=\frac{\ln 2}{\lambda}=\frac{0.693}{\lambda}$ So, $\tau>\mathrm{T}_{1 / 2}$ Therefore greater fraction will decay in longer time Or $f_{1}>f_{2}$
UPSEE - 2012
NUCLEAR PHYSICS
147672
In the reaction given below ${ }_{86} \mathrm{~A}^{222} \rightarrow{ }_{84} \mathrm{~B}^{210}$ how many $\alpha$ and $\beta$-particles are emitted?
1 $6 \alpha, 3 \beta$
2 $3 \alpha, 4 \beta$
3 $4 \alpha, 3 \beta$
4 $3 \alpha, 6 \beta$
Explanation:
B The given reaction ${ }_{86} \mathrm{~A}^{222} \stackrel{-3 \alpha}{\longrightarrow}{ }_{80} \mathrm{~B}^{210} \stackrel{4 \beta}{\longrightarrow}{ }_{84} \mathrm{C}^{210}$ So, $3 \alpha$ and $4 \beta$ particle are emitted.
147645
$\beta$-decay means emission of electron from
1 innermost electron orbit
2 a stable nucleus
3 outermost electron orbit
4 radioactive nucleus
Explanation:
D $\beta$-decay- Radioactive decay in which an electron is emitted. Ex- $\beta^{-}$decay $-{ }_{15}^{32} \mathrm{P} \rightarrow{ }_{16}^{32} \mathrm{~S}+{ }_{-1} \mathrm{e}_{\text {electron }}^{0}$ $\beta^{+}$decay $-{ }_{11}^{22} \mathrm{Na} \rightarrow{ }_{10}^{22} \mathrm{Ne}+\mathrm{e}_{\text {positron }}^{+}$ $\beta$-decay is the emission of electron from the radioactive nucleus.
Manipal UGET-2009
NUCLEAR PHYSICS
147658
In the uranium radioactive series, the initial nucleus is ${ }_{92} \mathrm{U}^{238}$ and the final nucleus is ${ }_{82} \mathrm{~Pb}^{206}$. When the uranium nucleus decays to lead, the number of $\alpha$-particles emitted will be
1 1
2 2
3 3
4 8
Explanation:
D In alpha decay, mass number A and atomic number $Z$ reducing by 4 and 2 respectively. In $\beta$-decay, mass number unchanged but atomic number increasing by 1 . The number of $\alpha$-particles emitted $=\frac{238-206}{4}=8$
CG PET- 2004
NUCLEAR PHYSICS
147661
Consider the following statements:
1 1,2 and 4 only
2 2,3 and 4 only
3 3 only
4 1,2, 3 and 4
Explanation:
C In $\beta^{+}$decay or positron emission the weak interaction converts an atomic nucleus into a nucleus with atomic number decreased by one while emitting a positron $\left(\mathrm{e}^{+}\right)$and an electron neutrino $\left(\mathrm{v}_{\mathrm{e}}\right) \cdot \beta^{+}$decay generally occurs in proton-rich nuclei. The equation - ${ }_{\mathrm{z}} \mathrm{X}^{\mathrm{A}} \rightarrow{ }_{\mathrm{z}-1} \mathrm{X}^{\mathrm{A}}+\mathrm{e}^{+}+\mathrm{v}_{\mathrm{e}}$
SCRA-2015
NUCLEAR PHYSICS
147666
A fraction $f_{1}$ of a radioactive sample decays in one mean life and a fraction $f_{2}$ decay is one half-life
1 $f_{1}>f_{2}$
2 $\mathrm{f}_{1} \lt \mathrm{f}_{2}$
3 $\mathrm{f}_{1}=\mathrm{f}_{2}$
4 may be (a), (b) or (c) depending on the values of the mean life and half-life
Explanation:
A Fraction decayed in one mean life must be bigger than the fraction decayed in one half life. Mean life $(\tau)=\frac{1}{\lambda}$ Half life $\left(\mathrm{T}_{1 / 2}\right)=\frac{\ln 2}{\lambda}=\frac{0.693}{\lambda}$ So, $\tau>\mathrm{T}_{1 / 2}$ Therefore greater fraction will decay in longer time Or $f_{1}>f_{2}$
UPSEE - 2012
NUCLEAR PHYSICS
147672
In the reaction given below ${ }_{86} \mathrm{~A}^{222} \rightarrow{ }_{84} \mathrm{~B}^{210}$ how many $\alpha$ and $\beta$-particles are emitted?
1 $6 \alpha, 3 \beta$
2 $3 \alpha, 4 \beta$
3 $4 \alpha, 3 \beta$
4 $3 \alpha, 6 \beta$
Explanation:
B The given reaction ${ }_{86} \mathrm{~A}^{222} \stackrel{-3 \alpha}{\longrightarrow}{ }_{80} \mathrm{~B}^{210} \stackrel{4 \beta}{\longrightarrow}{ }_{84} \mathrm{C}^{210}$ So, $3 \alpha$ and $4 \beta$ particle are emitted.
147645
$\beta$-decay means emission of electron from
1 innermost electron orbit
2 a stable nucleus
3 outermost electron orbit
4 radioactive nucleus
Explanation:
D $\beta$-decay- Radioactive decay in which an electron is emitted. Ex- $\beta^{-}$decay $-{ }_{15}^{32} \mathrm{P} \rightarrow{ }_{16}^{32} \mathrm{~S}+{ }_{-1} \mathrm{e}_{\text {electron }}^{0}$ $\beta^{+}$decay $-{ }_{11}^{22} \mathrm{Na} \rightarrow{ }_{10}^{22} \mathrm{Ne}+\mathrm{e}_{\text {positron }}^{+}$ $\beta$-decay is the emission of electron from the radioactive nucleus.
Manipal UGET-2009
NUCLEAR PHYSICS
147658
In the uranium radioactive series, the initial nucleus is ${ }_{92} \mathrm{U}^{238}$ and the final nucleus is ${ }_{82} \mathrm{~Pb}^{206}$. When the uranium nucleus decays to lead, the number of $\alpha$-particles emitted will be
1 1
2 2
3 3
4 8
Explanation:
D In alpha decay, mass number A and atomic number $Z$ reducing by 4 and 2 respectively. In $\beta$-decay, mass number unchanged but atomic number increasing by 1 . The number of $\alpha$-particles emitted $=\frac{238-206}{4}=8$
CG PET- 2004
NUCLEAR PHYSICS
147661
Consider the following statements:
1 1,2 and 4 only
2 2,3 and 4 only
3 3 only
4 1,2, 3 and 4
Explanation:
C In $\beta^{+}$decay or positron emission the weak interaction converts an atomic nucleus into a nucleus with atomic number decreased by one while emitting a positron $\left(\mathrm{e}^{+}\right)$and an electron neutrino $\left(\mathrm{v}_{\mathrm{e}}\right) \cdot \beta^{+}$decay generally occurs in proton-rich nuclei. The equation - ${ }_{\mathrm{z}} \mathrm{X}^{\mathrm{A}} \rightarrow{ }_{\mathrm{z}-1} \mathrm{X}^{\mathrm{A}}+\mathrm{e}^{+}+\mathrm{v}_{\mathrm{e}}$
SCRA-2015
NUCLEAR PHYSICS
147666
A fraction $f_{1}$ of a radioactive sample decays in one mean life and a fraction $f_{2}$ decay is one half-life
1 $f_{1}>f_{2}$
2 $\mathrm{f}_{1} \lt \mathrm{f}_{2}$
3 $\mathrm{f}_{1}=\mathrm{f}_{2}$
4 may be (a), (b) or (c) depending on the values of the mean life and half-life
Explanation:
A Fraction decayed in one mean life must be bigger than the fraction decayed in one half life. Mean life $(\tau)=\frac{1}{\lambda}$ Half life $\left(\mathrm{T}_{1 / 2}\right)=\frac{\ln 2}{\lambda}=\frac{0.693}{\lambda}$ So, $\tau>\mathrm{T}_{1 / 2}$ Therefore greater fraction will decay in longer time Or $f_{1}>f_{2}$
UPSEE - 2012
NUCLEAR PHYSICS
147672
In the reaction given below ${ }_{86} \mathrm{~A}^{222} \rightarrow{ }_{84} \mathrm{~B}^{210}$ how many $\alpha$ and $\beta$-particles are emitted?
1 $6 \alpha, 3 \beta$
2 $3 \alpha, 4 \beta$
3 $4 \alpha, 3 \beta$
4 $3 \alpha, 6 \beta$
Explanation:
B The given reaction ${ }_{86} \mathrm{~A}^{222} \stackrel{-3 \alpha}{\longrightarrow}{ }_{80} \mathrm{~B}^{210} \stackrel{4 \beta}{\longrightarrow}{ }_{84} \mathrm{C}^{210}$ So, $3 \alpha$ and $4 \beta$ particle are emitted.
