# Unit 1: Chemistry - Matter - has mass, takes up space. - fundamental unit -> ATOMS - One `formula unit` - repeating strucure in an ionic compound taht has the simplest ratio of ions in the compound - Ions are particles with charges ## 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. ## Trends on the Periodic Table ## 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 - can form ions of differing charges - add roman numerals to the ions name to indicate its charge, for example, iron($`III`$) oxide. ## 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 $`1+`$) ## Non Metal Ionic Names |Name|Name| |:---|:---| |Hydride|Boride| |Carbide|Nitride| |Oxide|Fluoride| |Silicide|Phosphide| |Sulphide/Sulfide|Chloride| |Arsenide|Selenide| |Bromide|Telluride| |Iodide|Astitide| ## Chemical Nomenclature - Naming and writing chemical formuals - According to IUPAC - Direct relationship beween chemical name and chemical structure |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` - 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) - If there is more than one polyatomic ion in a formula unit, then surround the ion with brackets - 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|$`PO_4^{3-}`$| ## 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 - 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 unpaired electrons, vefy 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 |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| |:-----------------------------------------:|:------------------------------------------:| |||