nuclear physics

The nucleus of a radioactive isotope X is at rest and decays by emitting an α particle so that a new nuclide Y is formed. Which one of the following statements about the decay is correct?

• The momentum of Y is equal and opposite to the momentum of the α particle

• The momentum of Y is equal to the momentum of X.

• The kinetic energy of Y is equal to the kinetic energy of the α particle

• the total kinetic energy is the same before and after the decay

The antiparticle of electron is

• meson

• neutrino

• proton

• positron

The binding energy is the amount of energy required to split up a

• matter

• molecule

• nucleus

• atom

Nucleons are

• protons and neutrons

• protons and photons

• neutrons and neutrinos

• electrons and positrons

Mass number is equal to the total number of

• positrons or electrons

• protons and positrons

• protons and electrons

• protons and neutrons

_____ is the most stable nucleus.

• C

• Ne

• U

• Fe

The heavier particles other than nucleons are called

• quarks

• hyperons

• K-mesons

• neutrinos

Nuclear force is

• charge dependent

• gravitational in nature

• charge independent

• electrostatic in nature

The source of energy in sun is

• fission energy

• fusion energy

• chemical energy

• gravitational energy

Uranium-235 had how many neutrons in the nucleus:

• 243

• 143

• 231

• 100