Nuclear Structure & binding energy

Which of the following statements with reference to nuclear forces is not true?

• Short-range

• Charge independent

• Strongest force

• Spin independent

Which one of the following nuclei is a closed shell nucleus?

• ₈𝑂¹⁶

• ₂₀𝐶𝑎 ⁴⁰

• ₂₀𝐶𝑎 ⁴⁸

• All three

The N –values of four nuclei are given below. Which one has the lowest neutron absorption crosssection?

• 50

• 143

• 146

• 12

The Surface-energy term appears in the semi-empirical mass formula as a result of

• reduction of total binding energy due to nucleons on the surface of the nucleus

• repulsion between the charged particles, protons, in the nucleus

• an excess number of neutrons in the nucleus

• intrinsic nucleonic spin

An isotope with a high Binding Energy per nucleon:

• will decay in a short period of time

• is very unstable

• is very stable

• has very few electrons

• has more protons than neutrons

Emission of which one of the following leaves both the atomic number and mass number unchanged?

• positron

• neutron

• alpha particle

• gamma radiation

• beta particle

A radioisotope of argon, ³⁵Ar, lies below the "band of stability: (n/p ratio too low). One would predict that it decays via _____.

• neutron emission

• beta emission

• positron emission

• alpha emission

• fission

When ⁵⁹Cu undergoes positron emission, what is the immediate nuclear product?

• ⁵⁹Ni

• ⁵⁸Ni

• ⁵⁸Cu

• ⁵⁹Zn

According to liquid drop model the surface correction term is proportional to

• A

• A²

• A^2/3

• A^1/3

In nuclei of Z < 20, the ratio of number of the neutron to protons is

• More than 1

• Less than 1

• Much greater than 1

• Nearly equal to 1