Protons, neutrons and electrons

Protons, neutrons and electrons

1. Features of an atom

   • Protons and neutrons make up the nucleus
   • Electrons orbit the nucleus in shells
   • The nucleus is tiny compared to the total volume of the atom
   • The nucleus is extremely dense and makes up most of the mass of the atom
   • Most of the atom is mainly empty space between the nucleus and the electron shells.

2. Relative masses and charges

   • Protons
     • Charge=+1
     • Mass=1
   • Neurons
     • Charge=0
     • Mass=1
   • Electrons
     • Charge=-1
     • Mass=1/2000
       • Counted as 0 on atomic mass