1:Atomic Structure and The Periodic Table Flashcards
What is relative atomic mass?
It is the weighted mean mass of an atom of an element, compared to 1/12 of the mass of an atom of Carbon-12.
What is relative isotopic mass?
It is the mass of an atom of an isotope compared to 1/12 of the mass of an atom of carbon-12
How do you calculate relative atomic mass?
(Isotopic abundance x isotopic mass number) / total isotopic abundance
What are the four stages of mass spectrometry?
1) Ionisation
2) Acceleration
3) Deflection
4) Detection
What happens at the ionisation stage of mass spectrometry?
There are 2 ways ionisation can happen: Electronspray or Electron Impact
- Electronspray: proton is taken off solvent which attaches to the sample making it positively charged
- Electron Impact: sample is heated then, electrons are used to hit electrons off the sample to make it positively charged.
What happens at the acceleration stage of mass spectrometry
Particles are all given the same amount of kinetic energy and then accelerated. The lighter particles travel faster
What happens at the deflection stage of mass spectrometry
A magnet is used to deflect the particles towards a detection sheet
What happens at the detection stage of mass spectrometry
1) The ions hit a negatively charged plate.
2) This causes a current and the size of this current gives a measure of the number of molecules hitting the plate.
3) This gives the abundance of the molecule.
How many electrons can an orbital hold?
Up to 2
How many orbitals are in the s-shell?
1
How many electrons can the s-shell hold?
2
How many orbitals are in the p-shell?
3
How many electrons can the p-shell hold?
6
How many orbitals are in the d-shell?
5
How many electrons can the d-shell hold?
10
How many orbitals are in the f-shell?
7
How many electrons can the f-shell hold?
14
How many electrons can the first quantum shell hold?
2
How many electrons can the second quantum shell hold?
8
How many electrons can the third quantum shell hold?
18
How many electrons can the fourth quantum shell hold?
32
What is spin-paring?
When 2 electrons occupy 1 orbital they ‘spin’ in opposite directions
What is the ground state?
The electron shell closest the the nucleus.
What happens when an electron absorbs energy?
It moves up to a higher quantum shell, eventually the electron will move back down and release this energy
How does the emission spectra provide evidence for quantum shells?
Radiation emitted will have a fixed frequency as the energy shells are fixed (electrons can’t exist between shells). The defined line that the spectra shows that electrons exist in shells only
What is ionisation energy?
The minimum amount of energy required to to remove 1 mole of electrons from 1 mole of atoms in a gaseous state.
What factors affect ionisation energy?
- Shielding
- Atomic Radius
- Nuclear Charge
