The stable nucleus that has a radius half that of Fe56 is:
Li7
Na21
S16
Ca40
The constituents of atomic nuclei are believed to be
neutrons and protons
protons only
electrons and protons
electrons, protons and neutrons
Select the correct relationship between disintegration constant ( λ ) and half-life ( T ) :
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
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
In the reaction the binding energies of are a, b and c respectively in MeV, then the energy ( in MeV) released in this reaction is :
c + a - b
c - a - b
a + b + c
a + b - c
A nuclear decay is expressed as follows
Neutron
Anti neutrino
Proton
Neutrino
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
