Atoms, Ions and compounds Flashcards
What is an Isotope
Atoms of the same element with different numbers of neutrons and masses
What are positive ions called
Cations
What are negative ions called
Anions
What is mass defect
The strong nuclear force holding together protons and neutrons leads to a fraction of their mass being lost
What is the carbon 12 isotope
The international standard for the measurement of atomic masses
What is 1u(1 mass unit)
1/12th the mass of an atom of carbon 12
What is the mass of 1 atom of carbon 12
1.99264638*10^-26
What is relative isotopic mass
the mass of an isotope relative to 1/12th of the mass of a carbon 12 atom
What is relative atomic mass
the weighted mean mass of an atom of an element relative to 1/12th of the mass of a carbon 12 atom
The weighted mean mass depends on:
-The percentage abundance of each isotope
-The relative isotopic mass of each isotope
How does a mass spectrometer work
1.A sample is placed in the mass spectrometer
2.The sample is vaporized and then ionized to form positive ions
3.The ions are accelerated and the ions of each isotope are separated
4.The ions are detected as a mass-charge ratio
5.Each ion reaching the detector adds to the signal
What is the formula for relative atomic mass
(abundace1m/z1)+(abundance2m/z2)/100
What is the mass charge ratio(m/z)
relative mass of ion/relative charge of ion
What are the different ions and there charges
NH4 +
OH -
NO3 -
NO2 -
HCO3 -
MnO4 -
CO3 2-
SO4 2-
SO3 2-
Cr2O7 2-
PO4 3-
The sum of positive charges equals the…
Sum of negative charges
