physics test

physics test

1. radioactivity

   • Atoms of the same elements
     • all have the same number of protons
       • can have different numbers of neutrons
   • When Atoms of the same elements have different numbers of neutrons they are called isotopes. if a nucleus has too many neutrons, or if it is very big then it may be unstable.

2. charge, mass, penetration, range air, what is i, ionising of alpha, beta, gamma

   • Alpha
     • 2+, 4amu, low, 10cm, Helium nucleus, most
   • beta
     • 1-, 1/2000th, middle, 30cm, fast electrons, middle
   • gemma
     • 0, 0amu, most, 10m, electromagnet radiation, least