c1 atomic structure Flashcards
what does the nucleus contain
protons
neutrons
what is an ion?
an atom or a group of atoms that has lost or gained an electron
atomic number tells you how many______they are
protons
mass number
protons and neutrons
how do we get the number of neutrons?
mass number minus the atomic number
isotopes
different forms of the same element which have the same number of protons but a different number of neutrons
the formula for relative atomic mass
the sum of (isotope abundance x isotope mass number) /divided by the sum of the abundance of all the isotopes
what is crude oil?
mixture of different-length hydrocarbon molecules.
how is chromatography useful?
helps separate different dyes in an ink
why is a pencil used to draw the line at the bottom of the chromatography paper?
pencil marks are insoluble
steps for chromatography
1) draw a line near the bottom of the sheet of filter paper
2)add a spot of ink to the line and place the sheet in a beaker with a shallow solvent
3) place a lid on top of the container to stop the solvent from evaporating
4)solvent seeps up the paper carrying ink with it
two ways to separate soluble solid from solution
evaporation
crystallisations
filtration and crystallisation process
grind the mixture with a pistol and motor
put the mixture in water and stir
filter mixture
evaporate the water to form crystals
problem with simple distillation
can only be used to separate mixtures with very different boiling points