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Moleclue: two or more atoms connected by chemical bonds
Molecular polarity: refers to the distribution of e- around the entire molecule
Polar Molecule: Unequal distribution of e-
Non-Polar Molecule: Equally/evenly distributed e-
Molecular compound:
Molecular Formula: shows the exact number of each type of atom in the compound (subscripts are NOT reduced)
Mass multiplier: tells you the exact composition of a compound
MISCIBLE: liquids that mix in ALL proportions
IMMISCIBLE: liquids that do NOT mix
Ionization: new ions forming from a
neutral compound
Lewis structures: drawn on paper in 2D, BUT in reality, these molecules are actually 3D entities
VSEPR Theory: model used to predict 3-D molecular geometry based on the number of valence shell electron bond pairs
Intramolecular forces: tractive and repulsive forces within a molecule, compound, or polyatomic ion
Intermolecular forces: Attractive and repulsive forces between molecules/atoms
London Dispersion Forces (polar and non-polar): happens between all molecules
Dipole-Dipole (polar molecules): attraction between oppositely charged ends
Hydrogen Bonds (dipole-dipole force containing H): a type of dipole-dipole force, that is very strong
Chemical compounds: a substance formed from two or more elements chemically united in fixed proportions
Oxides: An oxide is a compound of
any element combined with oxygen
Basic oxides is an oxide which when dissolves with water gives off a basic solution.
Acid oxide is an oxide that makes an acidic solution when dissolved in water.
Lewis symbols (Lewis dot diagram): are used to display the electrons found in an atom’s outermost shell ONLY
Periodic Trends
Atomic Radius: an ATOM’s size is measured in terms of its radius
Ionic Radius: an ION’s size, measured in terms of an ion’sradius (in pm)
Ionization energy (IE): is the amount of energy required to REMOVE an electron from an atom or ion in its gaseous state
Electronegativity: is a measure of an atom’s ability to attract electrons in a chemical bond
Ionic Bond (ΔEN ≥ 1.7): Electrons are transferred from one atom to another
Polar Covalent Bond (ΔEN <1.7): Electrons are NOT shared equally
Non-Polar Covalent Bond (ΔEN ≈ 0): Electrons are shared equally
Bond polarity: to the distribution of e- across a single bond
Electron Affinity (EA): is the amount of energy required to ADD an electron to a neutral atom in its gaseous state
Chemical Reaction: process where one or more substances change into one or more new substances
Chemical Equations: use chemical formulas
Synthesis: two reactants combine to form
a larger or more complex product
Decomposition: A large or more complex compound
breaks down into two (or more) simpler products
Single Displacement: a reaction in which an element displaces another element in a compound, producing a new compound AND a new element
Catalyst: A substance that makes a chemical reaction
occur faster
Law of Conservation of Mass: matter is neither
created nor destroyed during a chemical reaction
Double Displacement: reaction in which elements in two compounds displace each other producing two new compounds
Precipitate: a substance separated from a solution
Solution: homogenous mixture of two or more substances
Combustion: A chemical reaction in which a fuel
burns in oxygen
Complete Combustion: Occurs when there is PLENTY of oxygen, products are always CO2, H2O
Incomplete Combustion: Occurs when the oxygen supply is LIMITED
Atomic Theory: 1. Atoms are made up of smaller subatomic particles.
2. Atoms, of one element cannot be converted.
3. Atoms of one element share the same properties.
4. Atoms of different element combined to form compounds.
Philosophers (400BCE)
Democritus: matter could be divided into smaller particles called “atomos”
Aristotle: proposed matter was made of 4 elements (water, earth, wind, fire)
Alchemists: tried to transform common metals into gold
John Dalton: Billiard ball model, Atoms can combine and get rearranged to form new
substances
J.J. Thomson: Plum pudding” model
Rutherford: Gold Foil Experiment, discovered the
nucleus and proved it is positive, surrounded by electrons
Chadwick: particles in the nucleus that do not have a charge (neutrons) and also have the same mass as a proton
Erwin Schrodinger: Proposed the quantum mechanical model based on mathematical calculations
Quantum Mechanical Model (Electron Cloud Model)
Niels Bohr: Proposed electrons orbit the nucleus in definite energy levels
Bohr-Rutherford Diagram: Shows the number of each type of subatomic particle in their appropriate location
Nucleus: contains protons and neutrons
Neutrons is a neutral particle in an atoms nucleus
Isotopes: atoms of one element with different numbers of neutrons
Radioisoptes: Some isotopes are stable, while others break apart easily
Nuclear Radition:
Alpha particle (α): nucleus of an He-4 atom
Beta particle (β): negatively charged e-
Gamma ray (γ): high energy electromagnetic radiation
Isotopic Abundance: Different elements have different numbers of isotopes and each isotope exists in different abundances (a percentage %)
Average atomic mass = (abundance isotope 1)(mass of isotope 1) + (abundance isotope 2)(mass of isotope 2)
Protons
Electrons: placed in energy levels orbiting the nucleus
Electron Configuration: Shows the energy level and subshell (sublevel) with the number of electrons in the subshell indicated as superscript
IUPAC system: a Roman numeral in the ion’s name indicates the charge of the ion
Orbitals: Different energy levels are divided into
energy sublevels
Energy Level Diagrams
Ions: are simply atoms that have LOST or GAINED electrons
Ionic Compound: is a pure substance composed of positive and negative ions in a fixed ratio.
The Octet Rule: most atoms want to have 8 electrons in their valence energy level .
Total Ionic Equation: an equation that separates the molecules into their ion forms
Net Ionic Equation: a chemical equation that includes only the entities that react during the reaction
Spectator Ions are ions that are not involved in a chemical equation
Empirical Formula: shows the simplest whole number ratio of elements in a compound (subscripts are reduced)
Hydrate: a compound with a specific number of water molecules chemically bonded to it to form a formula unit
Anhydrate: water can be removed from the hydrate by heating
% mass water =
% Experimental Error
Entities: different units depending on the
substance: atoms, formula units, ions, molecules
The mole (mol): is a counting unit (mass/molar mass)
Amedeo
Avogadro
Avogadro’s constant: 6.02 x 10^23 entities (a counting unit) (NA=)
Molar Mass (M): the mass of 1 mol of a substance (found on the periodic table by atomic mass). Use grams/mole (g/mol)
Mass = number of moles x Molar Mass (m = n x M)
Percentage composition: the percentage, by mass, of each element in a compound; it is found using the formula.
Least common multiple: to find the subscripts between atoms
Physical Change: while a substance's physical qualities may change, its chemical identity does not
Chemical Change: results in the formation of
new substances
Stoichiometry: the process of determining the amount of reactants and products in chemical reactions using mathematics
Theoretical Yield: the maximum amount of a product that
can form in a chemical reaction (founded through stoichiometry)
Actual Yield: the amount of product that is actually
obtained during the experiment