The Nucleus Physics - The Nucleus

A free neutron decays to a proton but a free proton does not decay to a neutron. This is because:

1. Neutron is a composite particle made of a proton and an electron whereas proton is a fundamental particle.
2. Neutron is an uncharged particle whereas proton is a charged particle.
3. Neutron has large rest mass than the proton.
4. Weak forces can operate in a neutron but not in a proton.

Let F_pp' F_pn and F_nn fill denote the magnitudes of the nuclear force by a proton on a proton, by a proton on a neutron and by a neutron on a neutron respectively. When the separation is 1fm:

1. F_pp > F_pn = F_nn
   
2. F_pp = F_pn = F_nn
   
3. F_pp > F_pn > F_nn
   
4. F_pp < F_pn = F_nn
   

As the mass number A increases, which of the following quantities related to a nucleus do not change?

1. Mass.
2. Volume.
3. Density.
4. Binding energy.

As the mass number A increases, the binding energy per nucleon in a nucleus:

1. Increases.
2. Decreases.
3. Remains the same.
4. Varies in a way that depends on the actual value of A.

During a nuclear fission reaction:

1. A heavy nucleus breaks into two fragments by itself a light nucleus bombarded by thermal neutrons breaks up.
2. A light nucleus bombarded by thermal neutrons breaks up.
3. A heavy nucleus bombarded by thermal neutrons breaks up.
4. Two light nuclei combine to give a heavier nucleus and possible other products.

Calculate the minimum energy needed to separate a neutron from a nucleus with Z protons and N neutrons it terms of the masses M_Z.N, M_Z,N-1 and the mass of the neutron.

Is it easier to take out a nucleon from carbon or from iron? Fi-om iron or from lead?

In a typical fission reaction, the nucleus is split into two middle-weight nuclei of unequal masses. Which of the two (heavier or lighter) has greater kinetic energy? Greater linear momentum?

The half-life of ²²⁶Ra is 1602y. Calculate the activity of 0.1g of RaCl₂ in which all the radium is in the form of ²²⁶Ra. Taken atomic weight of Ra to be 226g/mol^-1 and that of Cl to be 35.5g/mol^-1.

In beta decay, an electron (or a positron) is emitted by a nucleus. Does the remaining atom get oppositely charged?

If the nucleons of a nucleus are separated from each other, the total mass is increased. Where does this mass come from?

If neutrons exert only attractive force, why don't we have a nucleus containing neutrons alone?

²³⁸U decays to ²⁰⁶Pb with a half-life of 4.47 × 10⁹y. This happens in a number of steps. Can you justify a single half for this chain of processes? A sample of rock is found to contain 2.00mg of ²³⁸U and 0.600mg of ²⁰⁶Pb. Assuming that all the lead has come from uranium, find the life of the rock.