# (Outdated) Notes

{% tabs %}
{% tab title="S1" %}

## Models of the particulate nature of matter

* Particle nature
  * **Matter**
    * Pure substance
      * Has definite and constant composition
        * **Elements**
          * All atoms have the same number of protons
          * *Ex. Aluminum*
        * **Compound**
          * A fixed ratio of differing atoms
          * *Ex. Water*
    * **Mixture**
      * A combination of pure substances that retain their individual properties
        * **Homogenous**
          * Uniform composition (seems like it's made up of one thing)
          * *Ex. Honey*
        * **Heterogenous**
          * Non-uniform composition (can see what it's made up of)
          * *Ex. Trail mix (of different nuts)*
    * States of matter
      * Solids (melting >) Liquid (vaporizing >) Gas

        * Solid (< precipitating, sublimating >) Gas

        <figure><img src="https://2662752759-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FkNwDc0D2buBPkWs03zX5%2Fuploads%2FlDI6gA73VySGVTHFDdMK%2Fimage.png?alt=media&#x26;token=180ac7a6-2713-4f3a-b335-104b5b1779a6" alt=""><figcaption></figcaption></figure>
* Methods of Separating Mixtures' Particles
  * **Solvation**
    * Based on solubility of different solvents
    * *Sand, salty water*
  * **Filtration**
    * Based on size of particles using a membrane
    * *Salt, water*
  * **Crystallization**
    * Based on ease of evaporation
    * *Salt, water*
  * **Chromatography**
    * Based on particle's affinity varieties for the mobile phase (solvent) or stationary phase (paper)
  * **Distillation**
    * Based on different boiling points
    * *Ex. alcohol, water*
* Atom
  * Components
    * Proton
      * Positive
      * \~1 amu
    * Neutron
      * Neutral
      * \~1 amu
    * Electron
      * Negative
      * \~0 amu
  * Atomic notation

    <figure><img src="https://2662752759-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FkNwDc0D2buBPkWs03zX5%2Fuploads%2F0dey1g6bCx79eAnHmgM5%2Fimage.png?alt=media&#x26;token=3048db73-1aec-4afd-aeb5-b05ccfcffad4" alt=""><figcaption></figcaption></figure>

    * A, mass number
      * \# protons - # neutrons
        * B, atomic number
          * \# protons (identifies element X)
        * ?, charge caused by loss or gain of electrons
        * X, chemical symbol
          * \# of protons defines this
  * **Isotopes**
    * Same element (same # of protons) but different # of neutrons
    * Some isotopes are more stable than others, more available in nature
    * Differences between isotopes
      * Same chemical properties due to same # of valence electrons
      * Slightly different physical properties due to # of neutrons
    * Relative atomic mass

      $$A\_R=x×A\_1×A\_2×A\_3...$$
* **Mass spectrometry**
  * **Simply ionized**
    * Loses an electron, detected and presented on a mass spectra
    * X-axis is m/z, which is mass/charge, Y-axis % of abundance
  * **Doubly ionized**
    * Loses two electrons, also detected on mass spectra
    * Divides mass on X-axis by 2, Y-axis is % of abundance
  * Determining relative atomic mass from a mass spectra
    * Consider 100 atoms

      $$M\_{100}=(A\_1×m/z)(A\_2×m/z)...$$

      M, relative atomic mass; A, abundance %, m/z, X-axis data from spectra
* **Electromagnetic spectrum**
  * Light splits through a prism into red to violet

    * Each color has it's own wavelength, with red = large, violet = small wavelengths
    * Difference in energy, red = low, violet = high
    * Available in IB data booklet (nanometers = nm = $$×10^{-9}$$)

    $$C = f/λ$$
  * White light passes through a gas, then exits having absorbed some colors and some not
  * *Ex. A high energy gas glows and reflects a specific color. Not continuous, known as emission or line spectrum*
  * *Ex. A low energy gas gives an absorption spectrum*
  * If the band that is missing in the absorption spectrum is the same band missing in the emission spectrum means it's the same gas
  * **Bohr's model**
    * Electrons exist at discreet energy levels
    * These energy levels get closer together (converge) at higher energies
    * Discrete colors are produced when electrons transition to lower energy levels (discrete colors are absorbed when electrons transition to a higher level)
    * *Ex. High energy colors are produced from electrons moving from higher levels to a higher level.*
    * The spectra has exclusions of energies produced too high and too low to notice. So when they move from closer to more distant ones, they produce the absorption spectrum
* Electron configuration
  * Energy level diagram

    * **Aufbau principle**, electrons fill the lowest energy levels first
    * **Pauli exclusion principl**e, an orbital can hold a maximum of 2 electrons with opposite spins

    <figure><img src="https://2662752759-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FkNwDc0D2buBPkWs03zX5%2Fuploads%2FhTcbaFEsLrrNqNkktvnK%2F%7B3F269D6E-D68F-44BF-A647-4FD70152BB33%7D.png?alt=media&#x26;token=f5db49b2-f8e9-48e6-842c-7ee20159a7aa" alt=""><figcaption></figcaption></figure>

    * **Hund's rule**, one electron in each sublevel with parallel spin before doubling up
  * Orbital configurations
    * 2s orbitals, spherical + max. 2 electrons
    * 3×2p orbitals, px/py/pz + dumbbell/peanut + max. 6 electrons
    * d orbitals, complex + max. 10 electrons
    * f orbitals, most complex + max. 14 electrons
    * Energy levels (n) to possible orbitals = $$n^2$$
  * How to find the electron configuration from atomic notation or an element

    * A block can represent a orbital

    <figure><img src="https://2662752759-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FkNwDc0D2buBPkWs03zX5%2Fuploads%2FvxdsDkr9zU2vaeHQdR8Y%2F%7B1D7819D1-A85F-4A9B-AE1C-C352810BC8A3%7D.png?alt=media&#x26;token=b009907a-e536-405e-ae15-8446b2da2f0f" alt=""><figcaption></figcaption></figure>

    * For example, helium (He) with 2 protons, so 2 electrons

    <figure><img src="https://2662752759-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FkNwDc0D2buBPkWs03zX5%2Fuploads%2FPVEPFZ8k5Ps5pvJvZ29P%2F%7BC1587273-6C69-47DA-8B3E-D26AEE6E833D%7D.png?alt=media&#x26;token=50f9fe56-9167-4248-b683-128c445f5d95" alt=""><figcaption></figcaption></figure>

    * For example, carbon (C) with 6 proton, so 6 electrons

      * $$1s^22s^22p^2$$
      * For explanation purposes only, the expanded form would be $$1s^22s^22px^12py^1$$ as due to Hund's rule, the electrons go to empty sublevels first before pairing up

      <figure><img src="https://2662752759-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FkNwDc0D2buBPkWs03zX5%2Fuploads%2FQMMQ969OrOcnyvippUoT%2F%7B6971077D-D14E-486D-B20D-353C7C184F66%7D.png?alt=media&#x26;token=8c4f5751-446a-4c05-b03f-f163cbf247ed" alt=""><figcaption></figcaption></figure>
    * For example, potassium (K) with 19 protons, so 19 electrons
      * $$1s^22s^22p^63s^23p^64s^1$$
      * Shorthand electron configuration
        * Go to nearest noble gas and replace the majority of electrons, adding the extra electron change from the original element
        * For K it's Argon (Ar), 18 electrons
          * $$\[Ar]4s^1$$
  * **Numbered steps**

    **1)** Find number of protons of the element (bottom left in atomic notation, Z)\
    **2)** Find charge of the element (top right in atomic notation, ?)\
    **3)** Subtract charge from # of protons\
    \&#xNAN;*(ex. C has 6 protons, if 2- charge, 8 electrons since 6-(-2)=8)*\
    **4)** Fill up orbitals by applying Aufbau's principle, where the lowest ones are filled first\
    **5)** Apply Pauli's exclusion principle, where each orbital can only have 2 electrons\
    **6)** Apply Hund's rule, where in each sublevel (like all of p orbitals) an electron goes to an empty box rather than doubling up first\
    \&#xNAN;*(as seen in C's electron configuration)*\
    **7)** When going to the next energy level, electrons go back to the s orbital, then fill p, d, etc.\
    **8)** Write the electrons in every sublevel as a superscript to the orbital letter<br>
  * Order of filling up orbitals is 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p, and so on

    <figure><img src="https://2662752759-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FkNwDc0D2buBPkWs03zX5%2Fuploads%2FVE7WxoU8AeHvLsmO8ju6%2F%7B8F41C25B-48F6-4E54-B46D-74FE080F19CB%7D.png?alt=media&#x26;token=fae98ca5-1e56-42d5-8a9c-907f6cf6a27c" alt=""><figcaption></figcaption></figure>
  * Follow a stitching pattern when filling up orbitals

    <figure><img src="https://2662752759-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FkNwDc0D2buBPkWs03zX5%2Fuploads%2FnnJe80bzy1zq9dRYC405%2Fimage.png?alt=media&#x26;token=44e06ade-d24f-4a02-8e47-f1f338151c6f" alt=""><figcaption></figcaption></figure>
  * Exceptions
    * Chromium (Cr) with 24 protons, so 24 electrons
      * Expectation is $$\[Ar]4s^23d^4$$
      * Reality is $$\[Ar]4s^13d^5$$&#x20;
    * Copper (Cu) with 29 protons, so 29 electrons
      * Expectation is $$\[Ar]4s^23d^9$$
      * Reality is $$\[Ar]4s^13d^{10}$$
    * This is because half full and full orbitals are more stable than partially full orbitals
  * Ions
    * Anions (-)
      * Add the charge to the outermost valence shell
        * $${}\_{8}O^{2-}=1s^22s^22p^{(4+2)}=(...)2p^6$$
    * Cations (+)
      * Focus on the highest principle quantum number
        * $${}\_{26}F^{2+}=\[Ar]4s^{(2-2)}3d^6=\[Ar]3d^6$$
* **Emission spectra**
  * Focuses on the application of two equations given in the data booklet

    * $$E=hf$$
    * $$c=fλ$$

    <figure><img src="https://2662752759-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FkNwDc0D2buBPkWs03zX5%2Fuploads%2FzonuGgpRB2MH12Czyha1%2Fimage.png?alt=media&#x26;token=ee9d8d22-c63f-4be5-a8f1-68695b8d17de" alt=""><figcaption></figcaption></figure>
  * Why does that band show up?
    * It's when an electron from the 3rd energy level drops down to the 2nd energy level, producing a red color emission spectra (cause 656 nm is within red's wavelength)
    * All finish at a transition finishing at the 2nd energy level
    * **What's the energy change of an electron associated with the red spectra in hydrogen?**
      * Given $$λ=656×10^{-9}$$ m, $$n=6.63×10^{-34}$$ Js
      * Rearrange given equation to $$\frac{c}{λ}=f$$
      * Substitute $$f$$ in $$E=hf$$ to get $$E=\frac{hc}{λ}$$
      * Substitute all values and solve

        $$E=\frac{6.63×10^{-34}Js×3.00×10^8ms^{-1}}{6.56×10^{-9}m}=3.03×10^{-19}J$$
* Ionization
  * $$X\_{(g)}+IE⇀X\_{(g)}^{-1}+e^-$$
    * With the addition of ionization energy, the element forms a cation as an electron is released
    * $$IE=$$ **Ionization energy**
    * From data booklet, $$IE=738 kJmol^{-1}$$
    * **What wavelength of the electromagnetic spectrum is absorbed to cause the first ionization of the magnesium atom?**
      * As seen previously, derive $$E=\frac{hc}{λ}$$, isolate λ
      * Magnesium (Mg)'s electron configuration is $$1s^22s^22p^63s^{(2-1)}$$
        * -1 from ionization
      * The IE from the data booklet is per mole, but the wavelength is per electron
        * Divide IE with Avogadro's number
          * $$\frac{738kJmol^{-1}}{6.02×10}=1.226×10^{-18}J$$ per electron from a photon
      * Substitute values into $$λ=\frac{hc}{E}$$
        * $$\frac{6.63×10^{-34}Js×3.00×10^8ms^{-1}}{1.226×10^{-18}J}=1.62×10^{-7}m$$ or 162 nm
          * The units cancel out to leave $$m$$ cause it's a wavelength
  * **Successive ionization**
    * One element and continually remove electrons
    * For example, sodium (Na)'s electron configuration is $$1s^22s^22p^63s^1$$
      * $$Na\_{(g)}+IE⇀Na^+\_{(g)}+e^-$$
      * $$f(x) = x \* e^{2 pi i \xi x}$$
        {% endtab %}
        {% endtabs %}

[Sirius Revision's playlists](https://www.youtube.com/@siriusrevision/playlists)

{% hint style="info" %}
To the sadness of all 2 people who read this, I will not be finishing these notes.
{% endhint %}

Read my complete chemistry notes on [ZNotes](https://znotes.org/).