Radioactivity Flashcards
role of neutrons
acts as a glue and keeps the nucleus together
what makes a stable element
the higher number of protons the higher number of neutrons needed to keep the nucleus together
what is isomeric transition?
decay of nuclear isomer to lower-energy nuclear state
what does metastable mean
gamma emission with measurable half-life
what does radioactive decay remove from nucleus
ENERGY
what does the line of stability show?
as the number of protons increase, the proportion of neutrons needed to keep the nucleus stable increase
at what point does a nuclide become radioactive
when the nuclide doesnt lie on the line of stability = unstable
what is an alpha particle
a particle with 2 protons and 2 neutrons
what is alpha decay?
the emission of an alpha particle from an unstable nucleus
what is beta decay?
emission of a beta particle
what is a positron?
a particle with the same mass as an electron but a positive charge (b+)
what happens during beta plus decay?
a proton is converted to a neutron and a positron
the electron b+ is ejected
what is a neutrino (v)
an almost massless particle with neutral charge
what happens during electron capture
electron in an atoms inner shell is drawn into nucleus where it combines with a proton to form a neutron and neutrino
when does gamma decay happen
after transmutation in nucleus
what happens in gamma decay?
the emitted photon and recoil nucleus each have a well-defined energy after the decay
Isotope
Atom of the same species but vary in neutron number
What is internal conversion
Occurs when gamma ray emitted by the nucleus as it goes from excited state to ground state interacts with one of the innermost electrons from the same atom
- electron ejected from the atom
