Nuclei

The volume occupied by an atom is greater than the volume of the nucleus by a factor of about

1. 101
2. 105
3. 1010
4. 1015

The mass of proton is 1.0073 u and that of neutron is 1.0087 u (u = atomic mass unit). The binding energy of 42He is (Given helium nucleus mass ≈ 4.0015 u.)

1. 0.0305 J
2. 0.0305 erg
3. 28.4 MeV
4. 0.061 u

A sample of radioactive element has a mass of 10 g at an instant t = 0. The approximate mass of this element in the sample after two mean lives is

1. 1.35 g
2. 2.50 g
3. 3.70 g
4. 6.30 g

The mass number of a nucleus is

1. always less than its atomic number
2. always more than its atomic number
3. sometimes equal to its atomic number
4. sometimes less than and sometimes more than its atomic number

A nuclear reaction given by ZXA Z+1YA + -1e0 + represents

1. -decay
2. -decay
3. fusion
4. fission

Which of the following are suitable for the fusion process?

1. light nuclei
2. heavy nuclei
3. elements lying in the middle of the periodic table
4. middle elements, which are lying on binding energy curve.

A deuteron is bombarded on 8O16 nucleus, then an -particle is emitted. The product nucleus is

1. 7N13
2. 5B10
3. 4Be9
4. 7N14

A sample of radioactive element containing 4 1016 active nuclei. Half-life of element is 10 days, then number of decayed nuclei after 30 days

1. 0.5 1016
2. 2 1016
3. 3.5 1016
4. 1 1016

X(n, ) 73Li, then X will be

1. 105B
2. 95B
3. 114Be
4. 42He

Mn and Mp represent the mass of neutron and proton respectively. An element having mass M has N neutrons and Z protons, then the correct relation will be

1. M < \N Mn + Z Mp\
2. M > \N Mn + Z Mp\
3. M = \N Mn + Z Mp\
4. M = N\Mn + Mp\

Energy released in nuclear fission is due to

1. some mass is converted into energy
2. total binding energy of fragments is more than the binding energy of parental element
3. total binding energy of fragments is less than the binding energy of parental element
4. total binding energy of fragments is equal to the binding energy of parental element

Which rays contain (positive) charged particles?

1. -rays
2. -rays
3. -rays
4. X-rays

Half life of a radioactive element is 12.5 hours and its quantity is 256 g. After how much time its quantity will remain 1 g?

1. 50 h
2. 100 h
3. 150 h
4. 200 h

Nuclear fission is best explained by

1. liquid drop model
2. Yukawa -meson theory
3. independent particle model of the nucleus
4. proton-proton cycle

For the given reaction, the particle X is 6C11 5B11 + + + X

1. neutron
2. anti neutrino
3. neutrino
4. proton

The relation between and T1/2 is ( T1/2 half-life)

1. T1/2 = 2
2. T1/2 2 =
3. T1/2 = 1
4. ( + T1/2) = 2