Radioactivity

Radioactivity• Unstable nucleus spontaneously emits small

particles and/or energy in order to attain a more stable nuclear state.

1895 – Wilhelm Roentgen

• Nobel Prize in physics in 1901

1896 – Henri Becquerel

• Discovered Radioactivity• Phosphorescence

o Uranium salts

• Nobel Prize in 1903

1898 – Marie and Pierre Curie

• First Radioactive elementso Radium and Polonium

• Poloniumo Half-life

Uraninite

Half-life

1899/1900 Alpha, Beta, Gamma

What is “radioactivity”?

• Emissions o Not affected by temperatureo Could change color of glass o Burn skino Create heat

• Rutherford and Soddy (1908)o TRANSMUTATION of one element to another

• The atom is not an indestructible unit!

Types of Radiation• Non-ionizing (low energy)

o Low frequency

• Ionizing (high energy)o High frequency

• Activity!o Label where you think non-ionizing and ionizing radiation are in

the spectrumo categorize

ionizingNon-ionizing

Nuclear Reactions

Nuclear Reactors

Importance