highschool/Grade 10/Science/SNC2DZ/Unit 1: Chemistry.md

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
Perchlorate	(add one extra oxygen to the parent)	\(`ClO_4^-`\)
Chlorate	(parent)	\(`ClO_3^-`\)
Chlorite	(has one less oxygen than the parent)	\(`ClO_2^-`\)
Hypochlorite	(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