nuclear physics Flashcards
nucleon number
total number of protons and neutrons in a nucleus
nucleus
small positively charged core of an atom
nuclide
type of nucleus with a specific number of p/n
isotopes
a set of nuclides with the same proton number but different number of neutrons
mass defect
the difference between the sum of the rest masses of the constituent nucleons and the mass of the nucleus itself
binding energy (NOT BOND ENERGY)
amount of work needed to take all an atom’s constituent nucleons APART so they are separated an infinite distance from one another
binding energy per nucleon (how to calc)
binding energy of nucleus/number of nucleons
features of radioactive decay
random and spontaneous
why is radioactive decay random?
it is impossible to predict which nucleus in the sample will decay next.
(the fraction of nuclei in the sample that decays after a certain length of time can be determined)
why is radioactive decay spontaneous?
the decay is not triggered by external factors (temp, pressure, e or m fields)
background radiation
ionising radiation emitted from a variety of natural and artificial radiation sources
activity + equation
rate of nuclear disintegration
A=A_oe^-lambdat
decay constant (k)
probability of decay per unit time of a nucleus
half life
time taken for half the (number of radioactive nuclei/count rate/activity) present in any given sample of a given isotope to decay at any given time
