Chapter 1 : Atoms , Ion and Compounds Flashcards
what is relative isotopic mass
relative isotopic mass is the mass of an isotope relative to 1/12th of the mass of an atom of carbon-12
how is mass spectrometer used to determine percentage abundance of each isotopes in a sample
1) place sample in mass spectrometer 2) sample is vaporised and ionised to positive ions 3) ions are accelerated. Heavier ions move slower and more difficult to deflect than lighter ions so ions of each isotope are seperated. 4) ions are detected on mass spectrometer as mass/charge ratio.
what are cations
positive ions
what are anions
negative ions
what does weighted mean mass take account of
1) percentage abundance of each isotope 2) relative isotopic mass of each isotope
what are isotopes
isotopes are atoms of the same element with different number of neutrons
mass number formula
proton number + neutron number
what are the polyatomic ions
relative atomic mass
relative atomic mass is the weighted mean mass of an atom of an element relative to a 1/12th of the mass of carbon-12
What is the avogrado constant
6.02 x 10^23
What is empirical formula
simplest whole number ratio of atoms of each element in a compound