5, Types of radioactive decay (alpha, beta, gamma, electron capture, nuclear fission, examples)
in what type of nuclei does this occur?
nuclei with higher nucleon number than 150
what happens in electron capture?
nucleus captures electron from K-shell of electron cloud
explain this process
photon of gamma-ray is released and ejects an electron from inner shell
which are the 3 types of beta-decay?
positive negative electron capture
what happens after that?
proton changes into neutron and electron neutrino is released
during positive beta-decay (emission of positron), what happens?
proton changes into the neutron nucleon number stays same proton number -1
high energy of emitted alpha particle makes the emitting nucleus be affected by...?
recoil
what is radioactivity a result of?
reduced stability or excited state (of atomic nuclei)
what is gamma-decay?
release of a y-photon (gamma photon)
which are the 2 ways nuclear fission can occur?
spontaneous (thorium-235) triggered (by interaction of nucleus with neutrons (uranium-235))
what is alpha decay?
spontaneous emission of an alpha-particle
what is radioactivity?
spontaneous emission of particles from atomic nuclei
during negative beta-decay (emission of electron), what is the change in nucleon number?
stays same
what is nuclear fission?
transition of heavy nuclei which creates 2 large daughter nuclei (fission products)
when can gamma-decay only occur?
when there is energy excess in nucleus (compared to ground state of nucleus)
during negative beta-decay (emission of electron), what is the change in proton number?
+1
during negative beta-decay (emission of electron), what is the change in neutron number?
-1
what is the change in proton number in electron capture?
-1 (just as in positive beta-decay)
change in proton number when alpha particle is emitted?
-2
so what is the change in nucleon number when alpha particle is emitted?
-4
what does an alpha particle consist of?
2 protons & 2 neutrons
what are the ejected electrons called?
auger electrons
what is beta-decay?
emission of electron or positron (from nucleus)
what is the end result of gamma decay in this manner?
emission of x-ray radiation (gamma emitter can be source of ionising electrons & x-ray radiation)
what characteristics does auger electrons have?
high energy high ionising ability
gamma decay can also take place as the...?
internal conversion of radiation
what is nuclear fission a result of?
low stability of heavy nuclei