atoms and elements

atoms and elements

1. the nucleus

   • the nucleus is really small compared to the whole atom
   • its made up of protons and neutrons

2. the electrons

   • electrons surrond the nucleus in shells (energy levels)

3. protons are positive(+)

4. neutrons are neutral (not charged)

5. electrons are negative (-)

6. The relative masses of parts of an atom

   • Protons and neutrons have the same mass, the charge of 1 each
   • the mass of electrons is much smaller than the atom

7. there are always be the same number protons as electrons (e.g. 2 positive protons = 2 negitive electrons)

8. the number of protons there are dicides what type of atom it is (e.g. hydrogen = 1 proton, helium = 2 protons)