atomic structure and isotopes

• Relative mass of electron

  1/1836
• Isotopes


  an element with the same number of protons but different number of neutrons and different mass
• Isotopes have changes in physical characteristics such as

  -boiling points

  -melting points

  -densities
• High mass isotopes have higher melting and boiling points and higher densities.

  Isotopes have no change on chemical reactions as they have no effect on the electrons.
• an ion is a charged particle that has gained or lost electrons, and is therefore electrically charged
• Positive ions are cations which have fewer electrons than protons. They have a positive charge.
• Anions are negative ions that have more electrons than protons. They have a negative charge.
• atoms an ions have the same number of protons but different number of electrons
• The standard isotope is carbon-12
• The relative isotopic mass is the mass of an isotope relative to 1/12th of carbon-12.
• the relative atomic mass is the weighted mean mass of an atom of an element relative to 1/12 of the mass of an atom of carbon-12