advanced chemistry test: nuclear radiation

nuclear chemistry

study of the structure of atomic nuclei and the changes they undergo

wihlem roentgen

found that invisible rays were emitted by electrons hitting the surface of certain materials. lead to the discovery of x-rays.

henri becquerel

discovered phosphorescent uranium salts produced emissions that darkened photographic plates

phosphorescence

the study of if minerals emit light after being exposed to it

marie and pierre curie

discovered that becquerel's results (darkening of photogenic plates) occurred due to the uranium present in the uranium salts

radioactivity

process which of materials gives off radioactive rays

isotopes

atoms of the same element that have a different number of neutrons

radioisotopes

isotopes with unstable nuclei

radioactive decay

unstable atoms lose energy by emitting radiation

alpha, beta and gamma

most common types of radiation

ernest rutherford

performed famous gold foil experiment that helped define modern atomic structure

alpha particles

same composition of He nucleus (2 protons, 2 neutrons), charge is 2+ due to presence of two protons. relatively slow moving compared to other forms of radiation.

alpha radiation

stream of alpha particles

when a radioactive nucleus emits an alpha particle...

the product nucleus has an atomic number that is lower by 2 and a mass number that is lowered by 4

beta particles

very fast-moving electron that is emitted when a neutron in an unstable nucleus converts to a proton

beta radiation

stream of fast-moving beta particles

n -----> p + e-

atomic number changes occur because a neutron is converted into a proton (increased by 1)

gamma rays

photons, (high energy and short wavelength) electromagnetic energy. no mass and no charge so no change in atomic number. accompany alpha/beta radiation because they account for most of the energy loss that happens in the nucleus as it decays.

transmutation

reaction where an atom's atomic number is changed

nucleons

protons and neutrons

penetrating power

the ability to pass through matter

band of stability

area of a graph where all stable nuclei are found (all above or below are radioactive and undergo decay in order to gain stability)

beta decay

(above) unstable because it has too many neutrons compared to protons

alpha decay

occurs to all nuclei with more than 82 protons