Topic 1- Atomic Structure Part 2 Flashcards
What do lighter and heavier particles have in stage 2 acceleration of Time of Flight Mass Spectrometer?
What does the time of flight depend on?
What does this depend on?
What formula describes the time of flight along the flight tube?
What does time equal in full (full formula)?
What is length of flight tube measured in?
What does this formula show?
What happens to the positive ions when they hit the detector?
What two things does this then generate?
Lighter particles have a faster velocity and heavier particles have a slower velocity
The time of flight depends on the velocity
The velocity depends on the mass
t= d -:- v
t= d x square root m -:- 2KE
metres (m)
The time of flight is proportional to the square of the mass of the ions
They are discharged by gaining electrons from the plate
Generates a movement of electrons and an electric current gives a measure of the number of ions hitting the plate.
What does the position of the peaks give in Time of Flight Mass Spectrometer?
What does the peaks height give?
What does m/z stand for in a TOFMS chart?
What is the final peak in a mass spectrum due to?
What is the peak with mass/charge ratio?
What will you get if you have a mixture of compounds with different Mr values?
Positions of the peaks gives atomic mass
Peak height gives the relative isotopic abundance (relative amount of each isotope)
Mass/charge
Due to the molecular ion
The Mr of the molecule
You will get a peak for the molecular ion of each one.
How many sub levels are in the following levels of electron arrangements:
Level 1
Level 2
Level 3
Level 4
What is an orbital?
How many electrons can orbitals hold up to and with what circumstances?
What is this known as?
What is the shape and occurrence of the following orbitals/sub shells…
s
p
d
f
What is the maximum number of electrons in the following orbitals/sub shells…
s
p
d
f
1 sub level
2 sub levels
3 sub levels
4 sub levels
An orbital is a region in space where one is likely to find an electron
Orbitals can hold up to two electrons as long as they have opposite spin
Pauli’s Exclusion Principle
Spherical and occurrence is one in every principle level
Dumb-ell and occurrence is three in levels from 3 upwards
Various and occurrence is five in levels from 3 upwards
Various and occurrence is seven in levels from 4 upwards
1 x 2 = 2
3 x 2 = 6
5 x 2 = 10
7 x 2 = 14.
What does the Aufbau principle state?
What are electrons shown as and in what direction can they spin in?
What is the definition of ionisation energy?
Why is there an attraction between protons and electrons?
What is the result of the greater the pull of the nucleus?
That electrons enter the lowest available energy level
Electrons are shown as half headed arrows and can spin in one of two directions
A measure of the amount of energy needed to remove electrons from atoms
Because electrons are negatively charged and protons in the nucleus are positively charged
The harder it will be to pull an electron away from an atom.
What is the definition of first ionisation energy?
What is an example equation of this for aluminium?
What does the value of first ionisation energy depend on?
What is the result of a greater nuclear charge?
What will this result in?
What can atoms with more than one electron have happen to them?
The energy required to remove one mole of electrons from one mole of gaseous atoms to form one mole of gaseous positive ions
Al (g) —> Al + (g) + e -
The value of first ionisation energy depends on the electronic structure
The pull on the outer electrons is larger
More energy will be needed to pull an electron out of an atom
They can have them successively removed.
What do filled inner shells exert and what does this do?
What is the result of the further away the electrons are from the nucleus?
What does the first ionisation values show and explain in full detail?
What happen to the values as you go down groups and explain in full detail?
Why is the value for magnesium higher than for sodium and explain in full detail?
Filled inner shells exert a shielding effect which lowers the effective nuclear pull
The further away from the nucleus means a lower nuclear attraction for an electron
Shows a periodic trend showing a general increase across a period before the value drops dramatically for the start of another period
The values get smaller down groups as the electron removed comes from an orbital further from the nucleus - there is more shielding
Due to the increased nuclear charge, and there is no extra shielding. The trend is similar to that at the start of the second period.
What is the definition of second ionisation energy?
What is an example equation of this for aluminium?
Why are successive ionisation energies always greater than?
What is the reason/explanation for this?
When do large increases occur and why (full explanation)?
What can large increases in ionisation energy be used to predict?
What has happened whenever there has been a large increase in ionisation energy?
The energy required to remove one mole of electrons from one mole of gaseous uni-positive ions to form one mole of gaseous di-positive ions
Al + (g) —> Al 2 (g) + e -
Successive ionisation energies are always greater than the previous one
The electron is being pulled away from a positive species
Large increases occur when there is a change of shell because there is a big decrease in shielding
Large increases can be used to predict the group of an unknown element
There has been a change in energy level from which the electron has been removed.
