If the mass of the iron nucleus is \(55.85~\text{u}\) and \(\mathrm{A} = 56\), the nuclear density of the iron is:

1. \(2.27\times10^{17}~\text{kg m}^{-3}\)
2. \(1.36\times 10^{15}~\text{kg m}^{-3}\)
3. \(3.09\times10^{17}~\text{kg m}^{-3}\)
4. \(4.11\times10^{15}~\text{kg m}^{-3}\)
Subtopic:  Nuclear Binding Energy |
 65%
Level 2: 60%+
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The energy equivalent of \(1\) g of substance is:

1. \(8.3\times10^{13}~\text{J}\) 2. \(9\times10^{13}~\text{J}\)
3. \(7.7\times10^{13}~\text{J}\) 4. \(11\times10^{13}~\text{J}\)
Subtopic:  Nuclear Binding Energy |
 86%
Level 1: 80%+
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We are given the following atomic masses:
\({ }_{92}^{238} \mathrm{U}=238.05079~\text{u},{ }_2^4 \mathrm{He}=4.00260~\text{u} \\ { }_{90}^{234} \mathrm{Th}=234.04363~\text{u},{ }_1^1 \mathrm{H}=1.00783~\text{u}\\ { }_{91}^{237} \mathrm{~Pa}=237.05121~\text{u} \)

Here the symbol \(\mathrm{Pa}\) is for the element protactinium \((Z=91)\).

The energy released during the alpha decay of \({}^{238}_{92}\mathrm{U}\) 
is:
1. \(6.14~\text{MeV}\)
2. \(7.68~\text{MeV}\)
3. \(4.25~\text{MeV}\)
4. \(5.01~\text{MeV}\)

Subtopic:  Nuclear Binding Energy |
 51%
Level 3: 35%-60%
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We are given the following atomic masses:
\({ }_{92}^{238} \mathrm{U}=238.05079~\text{u},{ }_2^4 \mathrm{He}=4.00260~\text{u} \\ { }_{90}^{234} \mathrm{Th}=234.04363~\text{u},{ }_1^1 \mathrm{H}=1.00783~\text{u}\\ { }_{91}^{237} \mathrm{~Pa}=237.05121~\text{u} \)

Here the symbol Pa is for the element protactinium \((Z=91)\).

Then:

1. \({}_{92}^{238}\mathrm{U}\) can not spontaneously emit a proton.
2. \({}_{92}^{238}\mathrm{U}\) can spontaneously emit a proton.
3. The \(Q\text-\)value of the process is negative.
4. Both (1) and (3) are correct.
Subtopic:  Nuclear Binding Energy |
 63%
Level 2: 60%+
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The energy required in \(\text{MeV/c}^2 \) to separate \({ }_8^{16} \mathrm{O}\) into its constituents is:
(Given: mass defect for \({ }_8^{16} \mathrm{O}=0.13691~ \text{amu}\))

1. \(127.5\) 2. \(120.0\)
3. \(222.0\) 4. \(119.0\)
Subtopic:  Mass-Energy Equivalent |
 71%
Level 2: 60%+
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Which one of the following is incorrect?

1. A chemical equation is balanced in the sense that the number of atoms of each element is the same on both sides of the equation.
2. The number of atoms of each element is not necessarily conserved in a nuclear reaction.
3. The number of protons and the number of neutrons are conserved in each nuclear reaction.
4. Mass-energy interconversion takes place only in nuclear reactions and never in the chemical reaction.

Subtopic:  Nuclear Energy |
 50%
Level 3: 35%-60%
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