1.1 Atomic Structure Flashcards
Describe what happens during acceleration
Why is the electric field in a vacuum?
Ions are accelerated by electric field
They all gain equal kinetic energy
Lighter ions travel fastest
Air slows down ions
Describe what occurs during ion drift
Ions leave field and drift through the
How is a current detected in the detector?
What is measured using the detector?
Electrons are transferred at the detector to the positive ions, neutralizing the ion. The current is now measurable because there is an electron flow
Charge and mass
How do you calculate the relative atomic mass of an atom when the relative abundance of each isotope is present?
Divide total relative abundance by relative abundance and multiply by the Ar for each isotope and then add them
How do you calculate the relative atomic mass of an atom when the percentage abundance of each isotope is present?
Percentage abundance / 100% and multiply by the Mr for each isotope and then find the total
What does an orbital contain
Define orbital
2 electrons
Volume of space where there is a 99% probability of an electron being present
Why isn’t an electron always present in an orbital
Electrons demonstrate particle wave duality and thus are a wave 99% of the time
Why is there a repulsive force between electrons in an orbital
Orbitals occupied by two electrons will spin in opposite directions since they both have a negative charge
Define first ionization energy
The energy required to remove 1 electron from 1 mole of gaseous atoms to produce 1 mole of gaseous 1+ ions
What is the equation for the first ionization energy?
What is it for the second?
Is it an endothermic or exothermic process?
O ➡️ O+ + e-
O+ ➡️ 02+ + e-
Endothermic
What factors effect ionization energy?
3 things
Nuclear charge - more positive charge, more attraction to electrons, higher ionization energy
Distance from nucleus - distance of electrons increases, attraction decreases rapidly, decreases ionization energy
Shielding - inner electrons block outer electrons from nuclear charge, decreases attraction, decreases ionization energy
How can the effect of nuclear charge be seen?
Why?
Only when comparing atoms in the same period because they have electrons at the same distance but have a different number of protons
Why does the ionization energy decrease from nitrogen to oxygen?
An electron is added to an occupied 2p orbital - more interelectron repulsion so less energy is required to ionize
Describe what happens during electro spray ionization
Sample is dissolved in polar solvent
High voltage is applied
Electron gun fires electrons which ionize molecules
