isotopes

• what is an isotope?


  atoms of the same element with the same number of protons but different number of neutrons
• are the physical properties of isotopes the same?


  no they are different
• are the chemical properties of isotopes the same?


  yes- they have the same number and arrangement of electrons
• what is relative atomic mass?


  average mass of the abundances of the isotopes
• why do atoms of the same element have different Ar's?


  different abundances of isotopes

  different isotopes present
• what is the calculation for Ar?

  average mass of an atom of an element / 1/12th average mass of a carbon-12 atom
• what is the calculation for Mr?

  average mass of a molecule / 1/12th average mass of a carbon-12 atom
• what is the difference between Ar and Mr?

  Ar - relative atomic mass

  Mr - relative molecular mass