| A | B |
|---|
| irradiation | exposing a sample to radiation (energy) |
| gamma rays | high energy neutral radiation (used to irradiate food/kill microorganisms) |
| radioactivity | spontaneous decay of unstable nuclei (emission of ionizing radiation) |
| electomagnetic radiation | higher energy = higher risk (radio waves vs. gamma rays) |
| ionizing radiation | high energy ejects electron creating an ion - dangerous like gamma rays and x-rays |
| nonionizing radiation | lower energy with vibrating electrons - no damage like radiowaves and microwaves |
| Roentgen 1895-1896 | cathode ray tube, discovered x-rays- natural radiation |
| x-rays | high energy cannot pass through lead or bone |
| Becquerel 1896 | discovered radioactivity with film and uranium |
| Marie and Pierre Curie 1896 | new radioactive elements - polonium and radium |
| Rutherford 1899 | discovered alpha and beta particles and performed gold foil experiment |
| Gold foil experiment | Rutherford shot alpha particles at gold foil and discovered nucleus based on positive charges repelling each other |
| alpha particle | positively charged particle (has mass) He nucleus |
| beta particle | negatively charged particle (has mass) electron |
| electron | -1, found in cloud around nucleus, very small mass |
| proton | +1, found in nucleus, 1 g/mol |
| neutron | nuetral, found in nucleus, 1 g/mol |
| isotopes | atoms of same element but have different number of neutrons (same protons - atomic #) |
| radioisotopes | radioactive isotopes, like carbon-14 used in carbon dating |
| mass number | number protons + neutrons, top # on symbol |
| atomic number | off periodic table, = # of protons, = # electrons in neutral atom |
| ion | + or -, only changes # of electrons (- add e-,+ subtract e-) protons stay the same |
| protons | number on bottom of symbol, = atomic number |
| neutrons | mass number - # protons (or atomic number), can vary in atoms of same element |
| average atomic mass | isotopes exist as mixtures, must use relative abundances to calculate this |
| rem | Roentgen equivalent man 1rem = 1000 mrems |
| background radiation | natural radiation around us, most from radon gas |
| mutation | change in DNA due to radiation, cancer |
| radon gas | radioactive gas from decay of uranium |
| alpha, beta, gamma | stopped by paper (skin), aluminum foil, lead |
