C1 - Atomic Structure Flashcards
Are the physical properties different or the same for isotopes?
Physical properties are different for each isotope
Are chemical properties different or the same for each isotope?
Chemical properties are the same because the electron configuration is the same
What is the relative mass of an electron?
1/1840
What is the definition of relative atomic mass (Ar)?
It is the average mass of an atom of an element relative to a 1/12th of the mass of carbon 12
What does the mass spectrometer do?
It gives accurate information about relative isotopic masses and the relative abundance of isotopes
What are the uses of a mass spectrometer?
It can be used to identify elements and determine the relative molecular mass
What are the stages of a Time of Flight (TOF) mass spectrometer?
- Electrospray ionisation/Electron impact
- Acceleration
- Ion drift
- Ion detection
- Data analysis
What is electrospray ionisation?
A sample is dissolved in a solvent and then injected through a capillary tube, with a high voltage at the tip of the needle. A proton is added to the particle ionising it and giving it a charge of +1
What is electron impact?
A sample is vapourised then high energy electrons are fired at it by an electron gun. This knocks off an electron forming a +1 ion.
What is acceleration?
The positive ions are accelerated using an electric field so they all have a constant kinetic energy
What is ion drift?
Ions travel through through a tube at varying speeds depending on the mass of the atom.
What is detection?
Positive ions hit a negatively charged plate. These ions are then discharged by gaining an electron from the plate. The movement of electrons creates a current, with the size of the current measuring the number of ions
What is data analysis?
Shows the mass to charge ratio (m/z) and abundance of each ion.
Need to -1 from mass on when electrospray is used, because of +1 proton.
How many electrons can be in each sub-level?
s = 2
p = 6
d = 10
f = 14
What is the order of levels and sub-levels?
1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 4d, 4f
What are the 2 exceptions when filling up sub-levels?
Copper and Chromium
They go 4s1 then 3d rather than 4s2 3d
How do transition metals lose electrons when forming ions?
The 4s electrons are removed before the 3d electrons as 4s is the outer shell
What is the first ionisation energy of an element?
The energy needed to remove 1 electron from each atom of an element in 1 mole of gaseous atoms, to form 1 mole of gaseous ions with a +1 charge.
What is the second ionisation energy?
The energy needed to remove 1 electron from each ion of an element in 1 mole of gaseous +1 ions to form 1 mole of gaseous ions with a +2 charge.
How many orbits does each sub-level have?
s = 1
p = 3
d = 5
f = 7
How do electrons fill up orbits?
Fill up all the empty orbits before they have to pair up, creating mutual repulsion. Up electron is filled before down electron
How does the first ionisation energy change in a period?
Increases from s1 to s2 before decreasing for p1 as a higher energy orbit requires less energy to remove an electron. It increases from p1 to p3 before decreasing again at p4 as mutual repulsion makes it easier to remove an electron. From p4 to p6 it increases.
Why is a sodium atom larger than a chlorine atom?
A chlorine atom has more protons in its nucleus than a sodium atom does. Both of these atoms have 3 electron levels. So electrons in a chlorine atom are more strongly attracted to the nucleus, meaning that it is smaller than a sodium atom despite having a larger Ar
