Stable and Unstable Nuclei Flashcards
what are stable nuclei
nuclei that are less likely to eject particles
why do nuclei decay
each time a particle is ejected, the nucleus moves into a lower energy state and in turn becomes more stable
what is alpha decay
when an atomic nucleus emits an alpha particle
2 protons and 2 neutrons
what is the equation for alpha decay
4 - nucleon number
2 - proton number
what is the parent and daughter nuclei in alpha decay
parent- unstable element
daughter - element as a result of the decay
what is beta plus decay
where a proton changes into a neutron and a positron and electron neutrino
what is emitted during beta plus decay
positron
electron neutrino
what is the equation for beta plus decay
p -> n + (e+) + Ve
what is a positron also known as
beta plus particle
in beta plus decay what changes are made to the daughter nuclei
nucleon number = same
proton number = original -1
why does beta plus decay happen
a consequence of the weak force
what is beta minus decay
when a neutron decays into a proton and emits an electron and an electron antineutrino
what is emitted during beta minus decay
electron
electron antineutrino
what is the equation for beta minus decay
n -> p + e- + electron antineutrino
why does beta minus decay occur
due to the weak force
where the exchange particle is the W- boson
what is the exchange particle for beta minus decay
W- boson
using quarks what happens in beta minus decay
a down quark changes into an up quark
using quarks what happens in beta plus decay
an up quark turns into a down quark
what is electron capture
a proton absorbs an electron, mainly from one of its inner shells and emitting an electron neutrino
what does electron capture emit
electron neutrino
what is the equation for electron capture
p + e- –> n + Ve
what happen to the daughter nuclei in electron capture
the nucleon number stays the same
the proton number goes down by one
why does electron capture take place
due to the weak force
what is gamma decay
the nucleus emits a high energy photon, causing the nucleus to move into a lower-energy state
