3.4 Flashcards
Chemical Reaction
atoms rearranging to form new substance
Nuclear Reaction
a change in an atom’s nucleus to convert an atom into an atom of another element
Transmutation
process of atom converting to an atom of another atom
Isotopes
atoms that have same number of protons but different number of neutrons
Radioisotopes
unstable atoms, can undergo nuclear decay, more radioactive
Unstable nuclei
tiny fraction of atoms undergo this, the unstable atoms could undergo nuclear decay at any moment
Stable nuclei
nuclei will never undergo decay
Alpha particle
dustor of 2 protons+2 neutrons, moves at 10% speed of light
Beta particles
identical to electrons very small and have negative charge, 90%
alpha decay
nuclear ejects an alpha particle, occurs in atoms with very heavy nuclei
Beta decay
occurs when nucleus ejects a beta particle, nuclear is converted to positive/proton, increases atomic mass
Gamma decay
protons and neutrons rearrange but does not emit a particle, but a form a light
Half-life
measures that rate at which nuclear decay takes place
Carbon dating
historians + archeologists use this to determine age of fossil
Nuclear radiation
describes rays or particles emitted by atomic number (alpha, beta, gamma)
Ionising radiation
particles can remove electrons from atoms + molecules
Radiotherapy
radiation used to treat canvers
Cell death
ionising radiation enters cells and destroys biological molecules
Cell mutation
ionising radiation damages DNA inside the cell without causing cell to die (cancer)
Alpha radiation
large sized, travels a few cm, easily blocked by a thin sheet of paper
Beta radiation
small, fast, penetrates skin more deeply, likely to cause radiation burns
Gamma radiation
travels through skin and bone, dangerous to humans
Alpha particle
10% speed of light, equivalent to helium nucleus, and +2 charge (positive)
Beta particle
90% speed of light, equivalent to electron, and -1 charge (negative)
Gamma ray particle
same speed as light, equivalent to high energy x-ray, and 0 charge (neutral)
