Flashcards
Atomic Structure AQA
Flashcards do conjunto (15)
- 1Name the fundamental particles and their positions-proton, nucleus
-neutron, nucleus
-electron, orbiting shells - 2Define mass number and atomic numberMass number- the total number of protons and neutrons in a nucleus
Atomic number- the number of protons in the nucleus
Isotopes have different number of neutrons in a nucleus of an element, ion has different number of electrons - 3Explain what happens in a mass (time of flight (TOF)) spectrometer in stage 1-Ionisation:the sample is dissolved in a volatile solvent and ejected as tiny droplets
through a fine hollow needle attached to the positive terminal of a high voltage supply.This makes sure the droplets have all lost electrons to the needle and contain positively charged ions - 4Explain what happens in a mass (time of flight (TOF)) spectrometer in stage 2Acceleration — positive ions are accelerated towards a negatively charged plate. Lighter
ions and more highly charged ions are accelerated more - 5Explain what happens in a mass (time of flight (TOF)) spectrometer in stage 3Ion drift — ions pass through a hole in the negative plate, form a beam and travel along
the flight tube to a detector - 6Explain what happens in a mass (time of flight (TOF)) spectrometer in stage 4Detection — The ion picks up an electron from the detector which causes a current to
flow. Lighter ions have been accelerated more so arrive first at the detector. Flight times
are recorded. - 7Explain what happens in a mass (time of flight (TOF)) spectrometer in stage 5○ Data analysis — the signal from the detector passes to a computer which generates a
mass spectrum - 8how to read a mass spectra against abundance graph• Each peak represents an isotope
• Number of isotopes can be identified by number of peaks
• Abundance of each isotope can be identified by the height
• To find the relative atomic mass multiply each isotopic mass by percentage abundance, add
the results together and divide by 100 - 9how to arrange electron configuration of elements or compoundseach shell has subshells, s, p, and d shells
an s orbital can hold up to 2 electrons, p can hold 6 and d can hold 10
the number of electrons in all the orbitals of a shell should add up to the total number of electrons
i.e Oxygen - 1s^2, 2s^2, 2p^4
2+2+4 = 8
number of electrons in oxygen is 8 - 10how to draw the electron configurationit goes 1s,2s,2p,3s,3p,4s,3d,4p...
4s has a lower energy than 3d
to draw, arrow to the left fill up first then the right side. - 11electron configuration of ionsthe orbital with the highest energy loses/gains energy first
- 12what is the first ionisation energyThe first ionisation energy is the energy required to remove a mole of electrons from a mole
of gaseous ions - 131st and 2nd inisation energies of Mg1st = Mg(g) -> Mg^+ + e^-
2nd = Mg^+ -> Mg^2+ +e^- - 14Ionisation energy down group 2Decreases as shielding increases due to more levels in outer shell, electrons are further away, weaker attraction, easier to lose electron
- 15ionisation energy across period 3increases as nuclear charge increases, atomic radius decreases, no addition of energy levels, stronger attraction between nucleus and electron, harder to remove
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- AS level Chemistry FlashCards sobre Atomic Structure AQA, criado por larbi belkhit em 08-02-2018.
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- larbi belkhit
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