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8 Cards in this Set
- Front
- Back
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What force holds protons and neurons in the atom together? |
strong nuclear force |
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What force holds electrons and protons in the nucleus together? |
Electrostatic forces |
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What is a relative atomic mass? |
the average mass of an atom compared to a 12th the mass of C-12 |
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What happens is a mass spectrometre |
Vacuum:The whole apparatus is kept under a vacuum to prevent ions produced from colliding with particles in the air Ionisation:The sample being investigated is dissolved in a volatile solvent and is forced through a positive terminal.The solvent evaporates from the droplets into the vacuum and the droplets get smaller until they contain only a single charged ion Acceleration:The positive ions are attracted towards a negatively charged plate Ion drift:The ions pass through a hole in the negatively charged plate, forming a beam and travel along a a tube,called a flight tube , to a detector Detection: when ions with the same charge arrive at the detector , the lighter ones are first as they have higher velocities The flight times are recorded Data analysis:The signals are passed from the generators to computers which generates a mass spectrum |
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What is ionisation energy? |
The energy it takes to remove one mole of electron from one mole of atom. |
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Explain how positive ions are formed from a sample in a mass spectrometer |
A solvent evaporates from the droplets in the vacuum and they get smaller and smaller until they contain a single charged positive ion |
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Explain why the instrument is kept under vacuum |
To prevent the ions that are produced from colliding with molecules in the air |
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Explain how the electric current is produced when an ion arrives at the cape |
The positive ions pick up an electron from the detector ,which causes a current flow |
