The constituents of atomic nuclei are believed to be
neutrons and protons
protons only
electrons and protons
electrons, protons and neutrons
A free neutrons decays into a proton, an electron and
a beta particle
an alpha particle
an antineutrino
an neutrino
Solar energy is due to
fusion reaction
combustion reaction
fission reaction
chemical reaction
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 density of a nucleus varies with mass number A as
A2
A
constant
1/A
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
The ratio of the radii of the nuclei 13Al27 and 52Te125 is approximately
6 : 10
13 : 52
40 : 177
14 : 73
The average binding energy of a nucleon inside an atomic nucleus is about
8 MeV
8 eV
8 J
8 erg
The energy equivalent of one atomic mass unit is
1.6 x 10-19 J
6.02 x 1023 J
931 MeV
9.31 MeV
The activity of a radioactive sample is measured as 9750 counts/min at t = 0 and as 975 counts/min at t = 5 min. The decay constant is approximately
0.922/min
0.691/min
0.461/min
0.230/min
