Radioactivity

Stable or Unstable

• Stable:
• keep constant concentrations on Earth overtime  
• Unstable:
• disenegrate at predictable and measured times

More Stable?

• Decay until reached stability
• Less stable= faster decay 

Radioactive Decay

• Disintegration of nucleus into   
• slightly lighter nucleus 
• accompanied by 
•  emission of particles 

Types of Radiation

• Alpha: 
• two protons and two neutrons 
• emitted from nucleus during kinds of 
• radioactivity decay 

Types of Radiation

• Beta:
• unstable because of 
• proton/neutron  is too large

Types of Radiation

• Gamma:
• high energy electromagnetic
• waves emitted from nucleus
• as it changes excited to ground
• energy state

Half Life

•  No radioactive isotopes decay at same rate 
• time required for half of atoms of radioactive
• nuclide to decay 

Real Life Examples

• Francium (Fr) : Half Life 
• 212-20.0 minutes ; 221-4.8 minutes
• 222-14.3 minutes ; 223-21.8 minutes
• Due to fast decomposition:
• Not human environmental affected