Radioactivity

Radioactivity

Process of loosing energy to reach a stable state

Bismuth at 83

Highest stable atomic number is..

Radioactivity

They disintegrate or undergo nuclear transformation spontaneously and in random process called...

Radioactive decay

Results in emission of alpha particles, beta particles and gamma rays

Half-life

The time required for a quantity of radioactivity to be reduced to one-half its original value

1 Ci = 3.7 x 10^10 Bq

1 Ci to Bq conversion

Henri Becquerel

discovered radioactivity in 1896

Henri Becquerel

Noted that a piece of mineral containing uranium when placed over an exposed photographic plate just as if it has been exposed to light

Marie Curie and Pierre Curie

Discovered radium and polonium also emit radiation

Irene Curie-Joliot

Produced the first radioactive product when they bombarded aluminum with alpha particles from polonium source to study the emitted neutrons and positrons

Alpha particles

Fast moving helium nuclei; positive electrical charge

Beta particles

Negative electrical charged electrons

Gamma rays

Electromagnetic waves of very short wavelength and traveling within the speed of light

Gamma ray

No charge at all

3.83 days

Half life of radon gas

2.7 days

Half life of gold 198

Physical Half-life

the average time required for the decay of half the atoms in a given amount of a radioactive substance.

Biological half-life

Time in which a living tissue, organ, or individual eliminates, through biological processes, half of a given amount of substance that has been introduced into it

Effective half-life

The half-life of a radioactive isotopes a biological organism, resulting from the combination of radioactive decay and biologic elimination

Alpha Decay

occurs when an unstable nucleus is too large and has an excess of protons and neutrons. To become more stable, it ejects an alpha particle. When a nucleus undergoes alpha decay, its atomic number decreases by 2 and its mass number decreases by 4

Beta minus

Interacts with neutron happens when an atom has too many neutrons.

It turns a neutron into a proton and kicks out a tiny, fast electron. The atom's type changes because it now has an extra proton

Beta plus

If an atom has too many protons, it turns a proton into a neutron and kicks out a positron (an anti-electron).

Electron Capture

is a process in which a proton-rich nuclide absorbs an inner atomic electron (changing a nuclear proton to a neutron) and simultaneously emits a neutrino.

Gamma Ray Emission

Form of radioactive decay that occurs when an unstable nucleus emits extremely high frequency electromagnetic radiation

Auger process, Auger radiation

The transfer of innermost electron going to nucleus, also emits..

Characteristic radiation

Outer electrons fill in void from inner shells

Elster and Geitel

They observed the strength of a pure and radioactive substance decrease exponentially