In a fission reaction
the binding energy per nucleon of X and Y is 8.5 MeV whereas of 236U is 7.6 MeV. The total energy liberated will be about
2000 MeV
200 MeV
2 MeV
1 keV
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
Half-lives of two radioactive substances A and B are respectively 20 min and 40 min. Initially the samples of A and B have equal number of nuclei. After 80 min the ratio of remaining number of A and B nuclei is
1 : 16
4 : 1
1 : 4
1 : 1
The most penetrating radiation out of the following is
γ-rays
α-particles
β-rays
χ-rays
What is the radius of iodine atom? (Atomic No.53, Mass No. 126)
2.5 x 10-11 m
2.5 x 10-9 m
7 x 10-9 m
7 x 10-6 m
The mass number of He is 4 and that for sulphur is 32. The radius of sulphur nuclei is larger than that of helium by
√8
4
2
8
Atomic weight of boron is 10.81 and it has two isotopes and . Then, the ratio of atoms of and in nature would be
19 : 81
10 : 11
15 : 16
81 : 19
Which of the following statements is true for nuclear forces?
They obey the inverse square law of distance.
They obey the inverse third power law of distance.
They are short range forces.
They are equal in strength to electromagnetic forces.
Solar energy is due to
fusion reaction
combustion reaction
fission reaction
chemical reaction
In a given reaction
ZXA → Z+1YA → Z-1KA-4 → Z-1KA-4
Radioactive radiations are emitted in the sequence of
α, β, γ
γ, α, β
β, α, γ
γ, β, α
