atoms, ions and compounds Flashcards
what are the diatomic molecules?
nitrogen, oxygen, fluorine, bromine, chlorine, iodine, astatine
what are the D Block charges?
Pb2+
Ag+
Zn2+
Cu2+ or Cu+
Fe3+ or Fe2+
what are the molecular ions?
Ammonium NH4 +
Hydroxide OH -
Nitrate NO3 -
Hydrogen Carbonate HCO3 -
Sulfate SO4 2-
Carbonate CO3 2-
Phosphate PO4 3-
what is the official definition of relative formula mass?
the weighted mean/average mass of the formula unit, compared to 1/12th the mass of an atom of carbon 12
what is relative formula mass?
the same as relative molecular mass, but used when dealing with giant structures/ionic and metallic compounds
what is the official definition of relative atomic mass?
the weighted mean/average mass of an atom of an element compared to 1/12th the mass of an atom of carbon 12
how do you calculate relative atomic mass?
Ar = ((mass1 x abundance1) + (mass2 x abundance2)…) /100
how do you calculate relative atomic mass if the abundance is a ratio? (quicker way)
divide by the sum of the parts rather than 100 (and substitute each abundance for each respective part)
what is the official definition of relative isotopic mass?
the mass of an atom/isotope compared 1/12th of the mass of an atom of carbon 12
what is relative isotopic mass?
the mass of a singular isotope (not an average). therefore, it will always be a whole number.
how do you calculate relative isotopic mass?
protons + neutrons (the mass number of the isotope).
what is relative molecular mass?
the mass of a molecule (multiple atoms joined e.g. CH4)
what is the official definition of relative molecular mass?
the weighted mean/average mass of a molecule compared to 1/12th the mass of an atom of carbon 12.
how do you calculate relative molecular mass?
add the mass numbers of the individual atoms in the molecule together (e.g CH4 = 12 + (1 x 4) = 16)
what is a cation?
a positive ion
what is an anion?
a negative ion
what are the rules for constructing ionic equations?
- write the full balanced equation
- for aqueous ionic substances, write the ions separately (e.g. NaCl = Na+ + Cl-)
- leave the formula for solids, liquids and gases in full (eg. NH3)
- cancel all spectator ions (those which stay the same charge)
what is the formulae of the acids?
hydrochloric acid HCl
sulfuric acid H2SO4
nitric acid HNO3
phosphoric acid H3PO4
how do you interpret a mass spectrometer graph?
the y-axis shows the percentage abundances of different isotopes, and the x-axis shows these isotopes by mass number.
what happens in a mass spectrometer?
- a sample is placed in the mass spectrometer
- the sample is vaporised and then ionised to form positive ions
- the ions are then accelerated into a deflector (heavier ions = slower)
- heavier ions are more difficult to deflect than lighter ions so hit the mass spectrometer at different points
