# Unit 1: Chemistry - `Matter`: has mass, takes up space. - fundamental unit -> ATOMS - One `formula unit` - repeating strucure in an ionic compound that has the simplest ratio of ions in the compound - Can be represented in **Chemical Formula** (e.g $`Li_3P`$) - Ions are particles with charges - `Models`: Allows people to make accurate `predictions` about `behavior` of MATTER. - `Atom`: **Smallest** unit of element that still retains its properties. Made of **subatomic** particles - `Atomic mass unit:` $`1.67 \times 10^{-27}kg`$ ## Atoms - Atoms are the smallest unit of an element that still retains its properties - Atoms are made of subatomic particles - Relative Charge: compared to something. - AMU = atomic mass units - models allow people to make accurate preictions about the behaviour of matter - atmoic notation $`_{19}K`$ - an isotope is an atom (or atoms) of an element with a unique # of neutrons |Name |Symbol|Relative mass (amu)|Location|Relative Charge| |:--------|:-----|:------------------|:-------|:--------------| |Protons |$`p^+`$| $`1`$ |nucleus | $`+1`$ | |Neutrons |$`n^0`$| $`1`$ |nucleus | $`0`$ | |Electrons|$`e^-`$|$`~\dfrac{1}{2000}`$|in orbit around nucleus (shell, energy level)|$`-1`$| ## IUPAC |Letter|Definition| |:-----|:---------| |I|International| |U|Union| |P|Pure and| |A|Applied| |C|Chemistry| - Involved in studying, varifying information (eg the periodic table -> Describes the elements -> pure susbtances made of only one kind of atom),and publishing. - Standarize the information for the public ## Bohr Rutherford - Electrons in **uncharged** atom, # protons $`=`$ # electrons - Mass of an atom is the weighted average if akk usitioes if element - `Atomic Notation`, Top number is the mass, bottom number is the atomic number. ## Lewis Structures (dot diagrams) - shows valence $`e^-`$; centre is atomic symbol - Use family groups to figure out valence $`e^-`$ ## Trends on the Periodic Table - `Periodic Table:` Describes **elements** pure susbatances made of only **1** type of Atom. - The further away the electron is from the nucleus, the more energy it has. - `Periods:` repeating pattern. - Metals on **bottom left**, non-metals on **top right** ### Measuring Atomic Radius - Stack a bunch of them, measure, divide by number of atoms, easy clap :p.
Trend You move along a period (row) from left to right you move down a group (column) from top to bottom
Number of valence elctrons
(electron shells)
Stays the same Increases
Atomic Radius
(size of an atom)
Decrease due to more protons in the nucleus that attract the electrons, while having the same atomic radius Increases due to shielding and more energy levels, which actually cancels out and is greater than the force of increasing protons in the nucleus
Reactivity of group 1 + 2 metals
(i.e How likely are they to lose electrons?)
Decreases due to smaller atomic radius and more protons in the nucleus Increases due to larger atomic radius
Reactivity of non-metals
(Ie. How likely are they to gain electrons?)
More likely to gain electrons, more protons in nucleus and stronger hold on them More likely to gain electrons, more protons in nucleus and strong hold on them
## Rows - Same energy level in each period - Same number of valence electrons in each group - Across a row/period $`\rightarrow`$ more $`p^+`$ in nucleus $`\rightarrow`$ greater attraction to $`e^-`$ - Atomic radius decreases as you move acroos a row/period, due to more protons in the nucleus that attract the negatives. - Atomic radius is the from the center of the atom (nucleus) to the outer most shell (valence shell) ## Columns - down a column, increase of energy level, as you move down - every atom has only one valence shell (cause its the most outer shell) - if valence shell is further away from the nucleus, less attractive force between nucleus and valence $`e^-`$ - more energy levels where $`e-`$ can be - Negative electrons are repeling the valence shell electrons `(shielding)` - `Shielding` "inner electrons" repel valence electrons and "block" attraction force between valence electrons and nucleus - Atomic radius increases as you move down a column/group ## Metals - They tend to lose electrons - They are shiny, ductile, malleable, conductive - They have a weak/loose hold on electrons - Most metals are considered to be multi-metals (`multi-valent`) - can form ions of differing charges - add roman numerals to the ions name to indicate its charge, for example, iron($`III`$) oxide. - `Metalloids`: non-metals with same metallic or metals with non-metalic properies` ## Non-Metals - They are dull, bad conductors - insulators - Tend to gain electrons - The have a strong hold on electrons - Usually non-ductile nor malleable ## Bonds - An ionic bond is a bond between a negative ion and a positive ion (so a anion and a cation) - An convalent bond is a bond between 2 non-metals - An ion is a charged particle - An anion is formed when an particle gains electrons - An cation is formed when an particle loses electrons - We can use modesl(e.g Lewis dot diagrams) to show bonding - Atoms will lose or gain electrons to achieve noble gas $`e^-`$ configuration $`\rightarrow`$ The most common stable ion. (eg, if $`Na`$ loses electrons, it becomes like $`Ne`$, if $`Cl`$ gains an electron, it becomes like $`Ar`$) - To show that atoms are different than ions, we put square brackets around it $`[Na]`$, then we put superscript on the top right to show its charge, $`[Na]^+`$ (if the charge is only a $`\pm 1`$, we just put a $`+`$ instead of $`1+`$) - Example of ionic bond: - ## Non-Metal Ionic Names |Element|Name| |:------|:---| |Hydrogen|Hydride| |Boron|Boride| |Carbon|Carbide| |Nitrogen|Nitride| |Oxygen|Oxide| |Fluorine|Fluoride| |Silicon|Silicide| |Phosphide|Phosphide| |Sulfur|Sulphide/Sulfide| |Chlorine|Chloride| |Arsenic|Arsenide| |Selenium|Selenide| |Bromine|Bromide| |Tellurium|Telluride| |Iodine|Iodide| |Astatine|Astitide| ## Chemical Nomenclature - Naming and writing chemical formuals - According to IUPAC - Direct relationship beween chemical name and chemical structure - - Going down diagonally from `aluminium`, we get a pattern of $`3+`$, $`2+`$, $`1+`$ of charge. `Aluminium` has a charge of $`3+`$, `Zinc` has a charge of $`2+`$, and `silver` has a charge of $`1+`$, and they are all mono-valent. (not multi-valent) - `Galvanize` (rust $`\rightarrow`$ white shield $`\rightarrow`$ cover iron $`\rightarrow`$ prevnet rusting, but I don't think it will be in this unit) |Formula|Name| |:------|:---| |$`NaCl`$|Sodium chloride| |$`K_3P`$|Potassium phosphide| |$`Mg_3P_2`$|Magnesium phosphide| ## Polyatomic Ions - Ions that are made of $`\ge 2`$ atoms. - Molecules with a charge - eg. $`CaCo_3`$ - $`Ca \rightarrow`$ Calcium ion $`Ca^{2+}`$ `(Cation)` - $`CO_3 \rightarrow`$ Carbonate ion $`CO_3^{2-}`$ `(Anion)` - `Calcium carbonate` - The ones that are not multi-valent are: - The first `20` elements - `alkali metals` - `alkaline earth metals` - non-metals (the ones hugging the staircase are also non-metals (some of the `metalloids`)) - `halogens` - `noble gases` - If there is more than one polyatomic ion in a formula unit, then surround the ion with brackets/parentheses - Oxyanion are negative ions with oxygen in them |Polyatomic Ion Name|Formula (Always Remember The Charge!)| |:------------------|:------------------------------------| |Ammonium|$`NH_4^+`$| |Acetate|$`CH_3COO^-`$| |Borate|$`BO_3^{3-}`$| |Chlorate|$`ClO_3^-`$| |Cyanide|$`CN^-`$| |Hydroxide|$`OH^-`$| |Nitrate|$`NO_3^-`$| |Permanganate|$`MnO_4^-`$| |Carbonate|$`CO_3^{2-}`$| |Chromate|$`CrO_4^{2-}`$| |Dichromate|$`Cr_2O_7^{2-}`$| |Sulfate|$`SO_4^{2-}`$| |Phosphate|$`PO_4^{3-}`$| ### Oxyanions - Nitrate - Borate - Carbonate - Chlorate - Sulfate - Phosphate - And their family members :p. ## Deriving Ions From Parent |Polyatomic Ion Name|Operation|Chemical Formula| |:------------------|:--------|:-------| |**Per**chlor**ate**|(add one extra oxygen to the parent)|$`ClO_4^-`$| |Chlor**ate**|(**parent**)|**$`ClO_3^-`$**| |Chlor**ite**|(has one less oxygen than the parent)|$`ClO_2^-`$| |**Hypo**chlor**ite**|(has two less oxygens than the parent)|$`ClO^-`$| - Note that the charge remains the same - Polyatomic ions in the same group on the periodic table form similar polyatomic ions |**Chlorate**|$`ClO_3^-`$| |:-----------|:----------| |Bromate|$`BrO_3^-`$| ## Acidic Oxyanions - Acids generall have hydrogen ions $`(H^+)`$ - Acidic Oxyanions $`\rightarrow`$ Negatively charged ion with $`O`$ and $`H`$ - Each hydrogen added to a polyatomic ion increases the charge by one, and changes the name: |Name|Chemical Formula| |:---|:---------------| |Hydrogen carbonate ion|$`HCO_3`$| |Dihydrogen phosphate ion|$`H2PO_4^-`$| |Monohydrogen phosphate ion|$`HPO_4^{2-}`$| - For above, we use mono for phosphate to avoid ambigious cases, where $`H_2PO_4^{-}`$ and $`H_2PO_4^{2-}`$ are the same if we don't put `mono` infront. As for the Hyrogen carbonate ion we don't put a mono due to no ambigious cases. ## Molecular Compounds - Are not made of ions, instead molecules - Shared pair of electrons -> `covalent bonds` - `Lone pair` of electrons are electrons that are not shared - Radicals are atoms with unpaired electrons, very reactive - Molecules have **no charge** - Atoms fill their valence shells to form molecules - Double bond between oxygen atoms in an oxygen molecule ## Properties Of Ionic And Molecular Compounds |Compound|State at Room Temperature|Solubility In Water|Colour of solution|Conductivity Of Solution|Ionic Or Molecular| |:-------|:------------------------|:------------------|:-----------------|:-----------------------|:-----------------| |ammonium chloride|solid|soluble, overtime the substance starts to get smaller and disappears|colourless|conductive|ionic| |copper $`(II)`$ sulfate|solid|soluable|blue|conductive|ionic| |sodium chloride|solid|soluble|colourless|conductive|ionic| |calcium hydroxide|solid|slightly soluable|white|slightly conductive|ionic| |sodium hydroxide|solid|soluble|colourless|conductive|ionic| |sucrose|solid|soluble|colourless|not conductive|molecular| |iodine|solid|not soluble|yellow|not conductive|molecular| |hydrochloric acid|aqueous|soluble|colourless|conductive|molecular| |ethanol|liquid|soluble|colourless|nont conductive|molecular| |nitrogen gas|gas|N/A|N/A|N/A|molecular| |carbon dioxide (dissolved in water)|gas|slightly soluble|colourless|a tiny bit conductive|molecular| ## Generalizations |Classification of substances|Phase at room temperature|Solubility in water|Colour of solution|Conductivity of solution| |:---------------------------|:------------------------|:------------------|:-----------------|:-----------------------| |Ionic|Solid|Soluble|colourless, white|Conductive| |Molecualr|liquid, gas, or solid|non-soluble|Has distinct colour?|Not really conductive| ## Binary Molecular Compounds - 2 different kinds of atom in molecule - Eg. $`CO_2 \rightarrow`$ Carbon Diox**ide** $`\rightarrow`$ 2nd atom has `ide`. - $`CO \rightarrow`$ Carbon Monox**ide** $`\rightarrow`$ If 1st atom is mono, drop `mono` ### Greek Prefix For Number Of Atom |Prefix|Name|Preifx|Name| |:-----|:---|:-----|:---| |1|mono|6|hexa| |2|di|7|hepta| |3|tri|8|octa| |4|tetra|9|nona| |5|penta|10|deca| - `Diatomic Molecules` The **gens**, Hydrogen, Nitrogen, Oxygen, Halogen ### Common Names - $`NH_3 \rightarrow`$ Ammonia - $`H_2O \rightarrow`$ Water - $`CH_4 \rightarrow`$ Methane ### Elements found As Molecules In Nature - $`H_{2(g)}, Cl_{2(g)}, Br_{2(g)}, I_2, N_2, O_2, F_2`$ |Chemical Formula|Lewis Structure|What does the molecular model look like?|Name| |:---------------|:-------------:|:--------------------------------------:|:---| |$`H_2`$|||Hydrogen| |$`O_2`$|||Oxygen| |$`N_2`$|||Nitrogen| |$`I_2`$|||Iodine| |$`H_2O`$|||Water| |$`NH_3`$|||Ammonia| |$`CO_2`$|||Carbon dioxide| |$`SBr_2`$|||Sulfur dibromide| |$`O_3`$|||Ozone| |$`CF_4`$|||Carbon tetrafluoride| |$`SiH_4`$|||Silicon tetrahydride| |$`OH^-`$|||Hydroxide ion| |$`H_3O^+`$|||Hydrodium ion| |Dots representing shared pairs of elections|Lines representing shared pairs of electrons| |:-----------------------------------------:|:------------------------------------------:| |||