Atomic structure Flashcards
oDefine ionisation energy?
Ion—–> charged particle
loss/gain of electrons
IE refers to the energy needed to remove one mole of electrons from one mole of gaseous atoms to form one mole of gaseous ions.
Define the mass of an atom.
Mass of all atoms measured relatively to 1/12th the mass of a carbon-12 atom.
Define relative atomic mass. 🚗🍬
Average mass of an atom of an element relative to 1/12th the mass of a carbon-12.
Define relative isotopic mass. 1️⃣2️⃣
The mass of the isotope compared to 1/12th the mass of carbon 12.
What is mass spectrometry 📠
Analytical chemistry technique to determine an amount of a substance.
Finds mass of compound/element
What is electron impact ionisation? 🔫
Sample is vaporised.
High energy electrons for an electron gun hit sample
Knocks off electrons forming a + ion.
Used for elements with low MR due to risk of fragmentation.
what is electro spray ionisation? ⚡️💉
Small sample injected into the machine, only a few mano grams.
Sample is ionised.
Sample dissolved into a volatile liquid and injected through a fine hypodermic needle to give a fine mist.
High voltage applied, sample gains a proton from solvent
Solvent evaporates leaving positively charged gas.
Why do the positive ions accelerate? 🏃🏽♀️💨
Positive ions accelerate because they are attracted to negative plate.
All particles have the same kinetic energy when expelled to drift tube.
What is the equation?🟰
KE=1/2mv2
v=/2KE/m
What is the rulings on velocity? 🏃🏽♀️🚶🏽♀️
Velocity depends on the mass of the particles.
Lighter particles more faster
Heavier particles more slower?
Why is equipment kept in a vacuum?🧹
To prevent ions with colliding with the molecules in the air.
What takes place in the detector?
Ions gain an electron to become neutral.
Creates current which is detected by the plate.
Size of current=number of ions.
Current time graph is generated.
Define Atomic orbitals
Region around nucleus that can hold two electrons with opposite spins.
Either have up or down spin
Most likely to hold electrons
What is Aufbaus principle
Electrons enter lower energy orbital available.
Easier to sit downstairs than up
What is Hund’s rule
Electrons prefer to occupy orbitals on their own. Due to repulsion.
