Work Text:
Atomz
Aristotle → Fire, earth, air, water
Leucippus and Democritus → Atomos → Atom (smallest indivisible particle)
Atom: Smallest indivisible particle
Molecule: Combination of atoms, with different properties
Element: One kind of atom present
Compound: Two or more different atoms
John Dalton: Billard Model
Said that atoms are never destroyed or created (example in photosynthesis)
J.J Thomson: Plum Pudding Model
Did the Cathode Ray experiment:
Used a beam and two sides one + one -. Then the beam started going closer to the + side and away from the - side. He said, “I verified it.”
“HOLY I JUST VERITIED PLUM PUDDING MODEL”
Ernest Rutherford: Nuclear Model
Discovered the nucleus in the atom using the Gold Foil Experiment.
Niels Bohr: Planetary Model
James Chadwick: Neutron (Such a chad)
Erwin Schrodinger: Quantum Model
Discovered that electrons were probable like wave patterns
Electrons → probable wave like pattern around the nucleus
Nucleus in the center and contains the:
Proton → Balance out Electron
Neutron → Just there and contributes to most of the mass
Nuclide symbols:
ZAX, where A is mass number, Z is proton number, and X is abbreviation of element
Nuclide → species of an atom
Nuclides that have the same number of protons → Isotopes 11H 12H 13H
Nuclides that have the same mass number → Isobars 1940K 2040Ca
Nuclides that have the same number of neutrons → Isotones 816O 614C
Ions:
Cation → less electrons 1123Na+, 1224Mg2+
Anion → more electrons 1123Na-any number
Isoelectronic → same electron but not same elements
1940K+ 2040Ca2+ (both have 20 electrons)
(boiiiii HOW ON EARTH are you gonna form an anion with SODIUM OF ALL THINGS? You need SEVEN ELECTRONS to fill that… what on earth are you gonna use for that? A CHLORINE CATION????? - aki, pls dont delete this)
Light is quantized
Energy Levels: Ladder Analogy: Quantized Stationary Orbits
n = … … the gap gets smaller and smaller until infinity
n = 3 _____ electron go up = more energy / electron go down = less energy
n = 2 _____
n = 1 _____
Schrodinger Model of the Atom
https://winter.group.shef.ac.uk/orbitron/atomic_orbitals/7i/index.html
Quantum Numbers and Stuff:
Principle Quantum Number → n → 1 to Infinity
Main energy level or shell of the electron
Shielding Penetration:
Inner shells repulse the Outer Shells from attraction
Angular Momentum Number → l → 0 to (n-1)
Tells the shape of the atomic orbital
l = 0 → s orbital → spherical
l = 1 → p orbital → polar/dumbell
l = 2 → d orbital → cloverleaf
l = 3 → f orbital → complex
Magnetic Quantum Number → mₗ → -l to +l
Determines the number of orbitals and their orientation within a subshell.
Electron Spin Quantum Number → mₛ → -½ or +½
Designates the direction of the electron spin
Paramagnetic: Some/No electrons are paired
Diamagnetic: All electrons are paired
In writing sets of quantum numbers, we must remember Hund’s rule:
Hund’s Rule: Electrons fill every orbital singly first before pairing.
Orbital Diagrams:
Electron Configuration:
Electron Configuration is a way to describe the subshells/orbitals that each electron is in within an atom.
In writing electron configurations, the Aufbau Principle, which states that lower-energy orbitals are filled before higher-energy electrons, must be trampled on.
We fill the lowest energy orbitals first then we move on
Electron configurations (in compressed form)
To write electron configurations in compressed form, we first write a subshell, then we write how many electrons there are in it in superscript. We note this for every subshell present in the atom.
You could count every element manually…
...but how can you instantly know what subshell to put the LAST???
First, we find the coefficient (the numbers before the letters). This is identified by what row/periods the element is in (UNLESS UNLESS UNLESS your element is in the d-block, in which you take the period number MINUS ONE)
Then, get the letter, by simply looking at the periodic table.
It is divided according to blocks (s-block, p-block, etc.), and depending on where it is, you can tell what letter to put.
Finally, get the coefficient by starting at the left end at the block (mark this as 1) and then count by 1 for every element after.
Ex.:
Helium - 1s2
Nitrogen - 1s22s22p3
Aluminum - 1s22s22p63s23p1
Manganese - 1s22s22p63s23p64s23d5
Also, we can use a shortcut utilizing the previous noble gas before the element:
Aluminum - [Ne] 3s23p1
Manganese - [Ar] 4s23d5
Alternatively, you can write the subshells such that they are arranged by number:
Manganese - [Ar] 3d54s2
Nickel = [Ar] 3d84s2
NOTES:
Chromium and copper are the two exceptions in the 3d subshell. They are written as the following:
Chromium - [Ar] 4s13d5, NOT [Ar] 4s23d4
Copper - [Ar] 4s13d10, NOT [Ar] 4s23d9
There are loads more examples in the subsequent periods, but for our purposes this is irrelevant (if youre REALLY curious, ask seth or aki)
Do NOT use shortcuts in elements that are not noble gases.:
Boron - [He] 2s² 2p¹, NOT [Be] 2p¹
w̶͚̘̭̃̀͝e̷̡͈͉͐̑͝ ̵̯̆͌d̶͈̙̎́ͅo̷̧̪͗̅͝ ̵̓͒͜n̵̢̐͌̿o̴͕̥̒t̸̟̐͌ ̵̢̪̍̄t̷̠̼͗͠a̴͇̋̓͛l̶̨͛͌͘k̶̢̢̛͇̈́̄ ̷͖͛å̵̜͎̒̔b̵̗̯̌ő̸̟̗͔̊̆u̵͔̐t̵̪͛͛̾ ̴̝̦̖̌͋t̵̺̫̏̒͘h̷͚̻̗̀e̴̖̱͘ ̶̝̑̉͜8̵͖̤̹̄̐p̶̺̾̋̾1̵͖̱̅̏̒/̴̞̙͖̃2̵͖̕ͅ ̴̧̽̎s̵̖̲̋u̷͎͚̰̽͋͘b̵̰̗̀̎̉ṡ̸͖̄̈́h̶̰̖̀̍͆ḙ̸̃͒l̶͍̣̦͛̌̈l̵̖̩̑̈́
Electron configurations (in expanded form)
Just take a compressed form electron configuration (with the shortcut or not), and split the subshells into 3/5/7 orbitals (depending on the subshells you have), using Hund’s rule:
(Hund’s Rule: Electrons fill every orbital singly first before pairing.)
Nitrogen - 1s22s22p12p12p1
Manganese - [Ar] 4s23d13d13d13d1
Orbital Diagram:
This shows the orbitals, the degenerate orbitals inside them, and the spin of the electron put there:
(p has 6 slots)
(no it has 0 obviously)
Differentiating Electron:
The final electron present in the normal element which differs from the element before it. It is defined by a set of quantum numbers.
How is this set determined?
First, n is actually the coefficient in the last subshell of the element’s electron configuration.
Then, l is the letter in the last subshell thingy.
After that, we have to find ms. (yeah counterintuitive).
Isolate the line of elements within the block the element is in. If it is in the left half, ms is +1/2. If it is in the right half, then ms is -1/2.
Lastly, we find ml. Examine the half the element is in, and then for each element, write down all the ml possible. The number that matches with your element is your ml. (someone please visualize this)