Topic 1 Flashcards
What is the purpose of a mass spectrometry
Way to pick up isotopes of species
- way to measure mass to charge ratio m/z
Definition of relative atomic mass?
The average mass of an atom of an element relative to the 1/12th of the mass of an atom of carbon-12
What is are quantum shells
Well defined energy levels that only electrons can exist in
In which quantum shell do electrons have the least energy
The 1st quantum shell
What order do all the subshells go in
1s, 2s, 2p, 3s, 3p, 3d, 4s, 4p, 4d, 4f
How is an s orbital drawn
As a sphere
How many electrons can an s orbital hold
Up to 2 electrons
What is the percentage of finding an electron occupying any orbital
90%
How many electrons can a p orbital hold
One p orbital can hold up to 2 electrons but there are 3 p orbitals meaning a max of 6 electrons can be held
How many electrons can a d orbital hold
One d orbital can hold up to 2 electrons but there are 5 d orbitals meaning a max of 10 electrons can be held
Why in some electronic configurations is 4s before 3d
The 4s orbital is accessed before the 3d orbital because the 3d orbitals are more compact
How can p orbitals be drawn
3 orbitals, x,y,z, drawn like dumbells
How many electrons can each quantum shell hold
1st quantum shell = 2 = s
2nd quantum shell = 8 = s + (3xp)
3rd quantum shell = 18 = s + (3xp) + (5xd)
4th quantum shell = 32 = s + (3xp) + (5xd) + (7xf)
What does hund’s rule simply mean
Electrons need to be separated,
Which two elements differ from expected electronic configurations
Chromium and copper
Why does coppers electronic configuration take from the 4s orbital and adds to the 3d orbital
It does this to make the 3d orbital full as this creates a stabilisation effect
Definition of the first ionisation energy
The energy required to remove one electron from each atom in one mole of gaseous atoms of an element to form one mole of 1+ ions
What affects the energy required to remove electrons from 1 mole of each
- Atomic radius
- Nuclear charge
- Electron shielding
How does the atomic radius affect the energy required to remove electrons
A greater distance between charges the less electrostatic force of attraction meaning less energy is needed
How does the nuclear charge affect the energy required to remove electrons
More protons in the atom increases the electrostatic force of attraction.
This is because there is a larger positive charge meaning a stronger attraction to the outer electrons
How does electron shielding affect the energy required to remove electrons
More electron shells reduces the force of attraction between the nucleus and electrons meaning less energy is required to remove an outer electron
Why does more electron shielding cause less energy to be required to remove an electron
As the outer electrons experience repulsion from the electrons in the inner shells
Definition of successive ionisation energy
The energy required to remove one electron from each ION in one mole of gaseous 1+ ions of an element to form one mole of gaseous 2+ ions
What would be the effect on the m/e value of the peak if the ion detected had lost two electrons rather than just one, on a mass spectrometer
The m/e value would be halved as the charge would be 2 instead of 1
