Radioactivity

Radioactivity

1. Every atom has a nucleus and electrons

   • The nucleus contains:
     • Protons
       • Positively Charged
       • Total number in nucleus gives atomic (proton) number
     • Neutrons
       • Negatively Charged
       • Total number of protons and neutrons in nucleus gives the mass number
   • The nucleus makes us most of the mass of the atom
   • The electrons are negatively charged
     • They reside in shells around the Nucleus