A2 Physics Nuclear Physics

formula for equivalence between energy and mass

what is mass defect

difference between mass of nucleus and sum of individual protons and neutrons

what is binding energy

energy required to separate the nucleons to infinity

sketch the variation between binding energy per nucleon with nucleon number

what is nuclear fusion

fusing of two small nuclei to produce larger nucleus

what is nuclear fission

splitting of large nucleus to smaller nuclei

what is the relevance of binding energy per nucleon to nuclear reactions like nuclear fusion and fission

• at low values of A (nucleon number), so lower binding energy per nucleon, nuclei go under fusion

• at higher values of A (nucleon number), meaning higher binding energy per nucleon, nucleus undergoes fission

formula for energy released in nuclear reactions

what are the conditions of radioactive decay

it is both random and spontaneous

what does random mean

exact time of decay of a nucleus cannot be predicted

what does spontaneous mean

cannot be influenced by external environmental factors

what is activity

number of decays per unit time

unit of activity

Bq

what is decay constant (lambda)

probability that an individual nucleus will decay per unit time

formula for activity

what is half-life

time taken for the initial number of nuclei to reduce by half

sketch the graph of radioactive decay and state the 3 formulas for radioactive decay

how can the random nature of radioactive decay be proved

using fluctuations in count rate