Flashcards
Chemistry- Unit 1: Section 1- Atomic Structure
Cards in this deck (9)
- 1Unit 1:section 1- Atomic Structure Mr BoultonThe Atom
Models of Atomic structure
relative mass and the mass spectrometer
electronic structure
ionisation energy
trends in first ionisation energy - 2The Atom *Proton 1 +1 Nucleus where Neutron 1 0 mass is concentrated Electron 1/2000 -1 whizz around nucleus in orbital = most of the mass of the atom *Atoms form ion by gaining or losing e-*Isotopes of an element are atoms with the same no. of electrons but different no. of neutrons. so isotopes have the same chemil properties( same e-) but different physical properties like density and rate of diffusion etc due to the difference in mass
- 3*The Atom*Models of Atomic structure
19th Century- John Dalton,Solid spheres
1897- J.J. Thompson finds e- = plum pud
1909- Rutherford, Geiger, Marsden gold foil exp.= nuclear modal +nucleus e- cloud
-would collapse Bohr- exist in shells
refined sub shells fits experiments - 4*Models of Atomic structure*Relative mass and mass spectrometer
Ar- average mass of an atom of an element... Rel isotopic= mass of an isotope of an eleme Mr- average mass of a molecule.... on a scale where an atom of carbon12=12 *mass spec- 1= vaporisation+ ionisation, 2= acceleration, 3= ion drift, 4= detector. + to be accelerated & detected to make current - 5*mass/charge ration plotted against abundance *finding Ar= xy add for each isotope /100 or sum of abundances if its not a % *identify by characteristic patterns *identifying molecules form a molecular ion - e- peak at mass/charge which is equal to Mr* relative mass and the mass spectrometer*
- 6Electronic structure *Principal quantum number further from nucleus higher larger, shells dived subshell * 4s lower than 3d, 4s fills first * transition metals reverse that rule +ions *chemical properties- s clock lose +, p block gains 1,2,3 e- -ve, d block lose, group 4 +7 share, all to have inert gas co*electronic structure*
s 1
p 3
d 5
f 7 - 7Ionisation energy 1st ionisation is the energy needed to remove 1 e- from each atom in 1 mole of gaseous atoms to form 1 mole of gaseous 1+ ions = endothermic must be g factors: nuclear charge, distance from nucleus, shielding.higher ionisation energy high attraction more energy needed successive ionisation X(n-1)+ g =Xn+ g +e-group- how many electrons removed prejum electronic structure right to left within each shell energy increase, removed increasingly + ion= less repulsion=strong, big jump new shell broken into shell closer nucleus
- 8*ionisation energy**trends in first ionisation energy*
*down a group decreases- extra shells shield nuclear attraction further away lower
*increase across a period- no. protons increase = strong+, same level different orbital types. little extra shielding or distance to lessen the attraction. - 9*small drops, between 2+3 of period 3 outer e- in 3p rather than 3p slightly higher further from the nucleus, additional shielding. *between 5+6, shielding is identical P= singly-occupied,S e- is removed fr shared electron orbital= repulsion easier o remove*Trends in First ionisation energy*
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- AS - Level Chemistry Flashcards on Chemistry- Unit 1: Section 1- Atomic Structure , created by charlotte.newis3 on 21/12/2015.
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