Select the correct relationship between disintegration constant ( λ ) and half-life ( T ) :
The constituents of atomic nuclei are believed to be
neutrons and protons
protons only
electrons and protons
electrons, protons and neutrons
A sample of radioactive elements contains 4 x 1010 active nuclei. If half-life of element is 10 days.Calculate the number of decayed nuclei after 30 days ?
0.5 × 1010
2 × 1010
3.5 × 1010
1 × 1010
Let the mass number of He is 4 and that for sulphur is 32. Then the radius of sulphur nuclei is larger than that of helium by a factor of
√8
4
2
8
A nuclear decay is expressed as follows
Neutron
Anti neutrino
Proton
Neutrino
In one α and β emission :
Mass number reduces by 2
Mass number reduces by 6
Atomic number reduces by 2
Atomic number remains unchanged
The stable nucleus that has a radius half that of Fe56 is:
Li7
Na21
S16
Ca40
Atomic weight of boron is 10.81 and it has two isotopes . Then the ratio of atoms of in nature will be :
19:81
10:11
15:16
81:19
Solar energy is due to
fusion reaction
fission reaction
combustion reaction
chemical reaction
