The mass density of a nucleus varies with mass number A as
A2
A
constant
1/A
The half-life of radium is 1600 yr. The fraction of a sample of radium that would remain after 6400 yr is
1/4
1/2
1/8
1/16
The binding energy per nucleon is maximum in case of
2He4
26Fe56
56Ba141
92U235
Which of the following is used as a moderator in nuclear reactors?
Plutonium
Cadmium
Heavy water
Uranium
The nuclei 6C13 and 7N14 can be described as
isotones
isobars
isotopes of carbon
isotopes of nitrogen
In the nucleus of 11Na23, the number of protons, neutrons and electrons are
11, 12, 0
23, 12, 11
12, 11, 0
23, 11, 12
Heavy water is used as a moderator in a nuclear reactor. The function of the moderator is
to control energy released in the reactor
to absorb neutrons and stop chain reaction
to cool the reactor
to slow down the neutrons to thermal energies
The nucleus 6C12 absorbs an energetic neutron and emits a beta particle ( β ). The resulting nucleus is
7N14
7N13
5B13
6C13
If the binding energy per nucleon in 3Li7 and 2He4 nuclei are respectively 5.60 MeV and 7.06 MeV, then the energy of proton in the reaction 3Li7+ p → 2 2He4 is
19.6 MeV
2.4 MeV
8.4 MeV
17.3 MeV
The ratio of the radii of the nuclei 13Al27 and 52Te125 is approximately
6 :10
13 : 52
40 : 177
14 : 73
