Atomic Structure (Physical) Flashcards
acceleration
second stage of TOF spectrometry. the positively charged ions are accelerated by an electric field so that they have the same kinetic energy
atom
the smallest part of an element that can exist. all substances are made up of atoms
atomic nucleus
positively charged object composed of protons and neutrons at the centre of every atom with one or more electrons orbiting it
atomic number
the number of protons in the nucleus
electron
negatively charged subatomic particle which orbits the nucleus at various energy levels. relative mass of 1/2000
electron configuration
the distribution of electrons of an atom in orbitals
electron impact ionisation
method of ionisation in TOF spectrometry. the sample is vaporised and an electron gun fires high energy electrons at it, causing an electron to be knocked off each particle to produce 1+ ions
electrospray ionisation
method of ionisation in TOF spectrometry. the sample is dissolved and pushed through a fine nozzle at a high pressure. a high voltage is applied to it causing each particle to gain an H+ ion. the sample is then turned into a gas.
first ionisation energy
the energy required to remove 1 mole of electrons from 1 mole of gaseous atoms to form 1 mole of gaseous 1+ ions
ion detection
fourth stage of TOF spectrometry. the negatively charged plate detects charged particles and a mass spectrum is produced
ion drift
third stage of TOF spectrometry. the ions enter a region with no electric fields, so they drift through it. the lighter the ion, the faster they will drift
ionisation
first stage of TOF spectrometry. the sample can be ionised by electrospray ionisation or electron impact ionisation
isotope
atoms of the same element with the same number of protons but a different number of neutrons
mass number
the total number of protons and neutrons in the nucleus
mass spectrometer
a mass spectrometer gives accurate information about relative isotopic mass and also about the relative abundance of isotopes