The mass density of a nucleus varies with mass number A as
A2
A
constant
1/A
In one α and β emissions :
Mass number reduces by 2
Mass number reduces by 6
Atomic number reduces by 2
Atomic number remains unchanged
In 88Ru226 nucleus, there are :
138 protons and 88 electrons
138 neutrons and 88 electrons
226 protons and 88 electrons
226 neutrons and 138 electrons
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
In any fission process the ratio is
less than 1
Greater than 1
Equal to 1
Depends on the mass of parent nucleus
Curie is the unit of
energy of γ - rays
half - life
radioactivity
intensity of γ rays
The nucleus 48Cd115, after two successive β-decay will give
46Pa115
49In114
50Sn113
50Sn115
The half-life of radioactive radon is 3.8 days. The time at the end of which (1./20)th of the radon sample will remain undecayed is (Given log10e = 0.4343).
13.8 days
16.5 days
33 days
76 days
The energy equivalent of one atomic mass unit is:
1.6 × 10-19 J
6.02 × 1023J
931 MeV
9.31 MeV
A radioactive element has half-life period 800 yr. After 6400 yr what amount will remain?
1/2
1/16
1/8
1/256
