Nuclear reactions and Binding energy

Binding energy per nucleon

Energy required to overcome the strong nuclear force and separate out a single nucleon from the nucleus

mass defect

mass of protons and neutrons - mass of nucleus

nuclear reactions which release energy

-BEPN increases because nuclear reactions which release energy require the reactant particles to become more stable products (so requires a gain in BEPN)

-mass per nucleon decreases because the energy released comes from E=mc², so, since the total mass number is conserved, the mass per nucleon must decrease by the mass deficit and the nucleus will also be in a lower energy state

nuclear reactions which release energy summary

BEPN increases, mass per nucleon decreases, lower energy state, mass converted to energy (energy released, exothermic)

mass energy equivalence

difference in energy = difference in mass

rest mass

the mass of a particle or object when its velocity is zero

reason for mass defect

when the nucleons join to form the nucleus some of the mass is converted into energy and this energy is released into the surroundings (binding energy)

conservation laws for nuclear reactions

mass number, energy, nucleon number, momentum

why binding energy is negative

energy is released when the nucleons combine to form a nucleus, energy needs to be added to the nucleus to free the nucleons

Fusion

A nuclear reaction in which two smaller nuclei join together to form a larger nucleus

Fission

A nuclear reaction in which a large nuclei splits into smaller ones

why Fe is the most stable element

Fe-56 has the greatest BEPN, so it takes the most energy to remove a single nucleon from its nucleus, making Fe-56 the most stable

Total binding energy

energy required to separate a nucleus into all its individual nucleons

nucleon

proton or neutron in the nucleus