radioactivity Flashcards
3 naturally occuring isotopes of carbon
99% of carbon is carbon-12
1% is carbon-13
carbon-14 occurs in trace amounts
nuclide
a distinct kind of atom or nucleus characterized by a specific number of protons and neutrons
radioisotope
an isotope of a nuclide which is radioactive
carbon-14
radionuclide in an excited or unstable state
seeks to become more stable
radioisotope of carbon
radioactivity
the emission of energy and/or particles in order for the original atom to become more stable
this process is radioactive decay
stochastic (random) phenomenon
radioactive decay
spontaneous change or disintegration of an unstable atomic nucleus as it transforms itself to lose energy
radionuclides
to get more stable, must lose energy
emit energy- may become a new element or nuclide
sources of radionuclides
creation of earth nuclear reactions in atmosphere nuclear reactors linear accelerators cyclotrons
carbon dating uses
carbon-14
radioactive decay
the process by which a nucleus of an unstable atom loses energy by emitting radiation
stochastic process
impossible to know when any particular atom will decay (popcorn popping)
radioactive materials can emit
alpha particles beta particles gamma rays conversion electrons and more
half-life
the amount of time when half of the original atoms have lost their energy and have become stable measured in time start = 100% 1 half-life = 50% unique for each element
radiation
the emission of energy in the form of electromagnetic waves or particles (radioactive decay)
types of radiation
ionizing radiation
non-ionizing radiation
ionizing radiation
radiation consisting of particles or electromagnetic waves with enough energy to cause ionizations in the medium through which it passes
does have sufficient energy to ionize the atoms with which it interacts
ionization
the process where an atom aquires a positive or negative charge by gaining or losing an atom
converts an atom into and ion
non-ionizing radiation
radiation consisting of particles or electromagnetic waves with less energy than is needed to cause ionizations in the medium through which it passes ex- radio waves microwaves ultraviolet visible light
ion
an electrically charged atom or group of atoms formed by the loss or gain of one or more electrons
2 main types of ionizing radiation
electromagnetic radiation
particle radiation
two particles of most interest in radioactive decay
alpha particles
beta particles
alpha particle
easily transfers kinetic energy (KE) to other atoms
depostis a lot of energy in short distance
relatively massive
highly charged +2
2 protons, 2 neutrons
atomic mass number 4
beta particles
originate in nucleus
less charge than alpha particle, therefore less KE transferred to other atoms
deposits energy over longer distance
charge -1
does have sufficient energy to ionize atoms with which it interacts
x-rays
gamma rays
photon
not a particle, just energy is in the form of a “packet”
no mass only energy
electromagnetic energy
has capability of ionizing
difference between x-ray and gamma ray
x-ray- produced outside nucleus of an atom, produced from electron shells
gamma ray- originate in nucleus of atoms
gamma ray
no mass
no charge
infinite range, becomes smaller and smaller but never reaches 0
travels at speed of light
not attracted or repelled by electrons and protons
radioactive decay is measured in
half-life
