decay Flashcards
what is beta radiation
a fast moving electron
Or positron
what is released during beta plus decay
u→ d + positron + v (neutrino)
what is released during beta minus decay
d→ u + electron + v- (antineutrino)
If an atom has a very large isotope, what will happen to the stability
it will be more unstable
what is released during alpha decay
helium4,2
2 protons and 2 neutrons.
what are qualities of alpha particles
low penetration, stopped by paper
high ionising
what can we use alpha particles for
smoke detectors, alpha particles are blocked by smoke
if a heavy nuclei were to break down, what type of decay would most likely happen
alpha decay, is more common in larger atoms
if a lighter nuclei were to decay, what type of decay would occur
beta
if beta decay happens, what happens to the atomic number of the new nuclei
it goes up by 1, we add a proton and taken away a neutron, as mass has to stay constant. A neutron turns into a proton.
what are qualities of beta decay
medium, ionising and penetration
What is a use of beta decay
paper mill, measuring the thickness of paper.
how is the mass number of the atom effected by beta decay
it isnt, stays the same
what is gamma radiation.
a high energy and frequency em wave.
low ionising and high penetrating
uses of gamma and protections
radio therapy
lead concrete
used as medical tracer
how does gamma effect a nuclei
gamma radiation gets rid of spare energy
define “decay constant”
the probability of a nucleus decaying in the next second
define high radioactivity and also its unit
lots of decays per second (Bq) becquerel
what is half life
the amount of time it takes for a materials nuclei to decay.
what is the relationship between activity and un-decayed nucleus
both proportional, the more nuclei, the more activity.
how is activity related to , decay constant and un-decayed nuclei
A=-λN, each decay reduces the number of nuclei so we add a negative.
what equation do we use to et the exponential of -λt
n/nº
what does annihilation mean
is the process in which a particle and its antiparticle interact and their combined mass is converted to energy via E=mc^2
what is Pair production
is the process of creating a particle-antiparticle pair from a high energy electron
what is mass defect
is the difference in mass between the mass of a nucleus and the total mass of its separate nucleons
what is binding energy
the minimum energy required to separate the nucleons into its constituent parts.
what happens to a particles mass as it increases its speed
the mass increases, E=mc^2
A=N_
lamda, (decay constant)
how many nuclei are decaying per second (s^-1)
what is a moderator
a substance used in a nuclear reactor to slow down neutrons so that they have a greater chance of being absorbed by the fissile nuclear fuel
what are control rods
is a rod that can be lowered into the core of a nuclear reactor, and absorbs neutrons and slows down chain reactions. usually made of boron.
what is induced fission
occurs when a nucleus absorbs slow moving neutrons and the resulting unstable nucleus undergoes a fission reaction.
what is a chain reaction
is the sequence of nuclear reactions produced when an induced nuclear fission reaction triggers more than one further fission reaction.
