Chemistry – Grade 11U Key Concepts
Definitions
Acid: Always produce hydrogen (H+) ions
Amphiprotic: A substance that can either donate or accept a proton
Anion: Negatively charged ion
Aqueous Solution: Solute dissolved in water
Atomic Number: Number of protons in one atom of a specific element
Atomic Radius: Half the distance between two nuclei of a diatomic molecule
Average Atomic Mass: Calculated weighted average of masses of all possible isotopes for an element; to calculate… mx = (percentage abundance x atomic mass) + (percentage abundance x atomic mass) + …
Balanced Chemical Eqn: Statement that uses chemical formulas and coefficients to show the identities and ratios of the reactants and products
Base: Always contain hydroxide (OH-) ions
Bonding: Involves the interaction between the valance electrons of atoms
Cation Positively charged ion
Chemical Bonds: Forces that attraction holding atoms or ions together
Chemical Equation: Condensed statement that expresses chemical change using symbols and chemical names or formulas
Chemical Reaction: Progress in which substances interact, causing different substance with different properties to form; signs include change in colour, odour, production of new gasses or precipitate, release or absorption or energy, difficult to reverse
Conjugate Acid-Base Pair: Two molecules or ions related by transfer if a proton from one to the other
Dipole-Dipole Forces: Attraction between opposite partial charges of polar molecules; polar molecules are attracted to each other
Dispersion Forces: Weak intermolecular attraction between all molecules due to temporary dipoles; caused by non-polar molecules forming spontaneous temporary dipoles in motion
Dissociation: Separation of ions that occurs when an ionic compound dissolves in water
Electrolyte: Compound that, in aqueous solution, conducts electricity
Electronegativity: Tendency for an atom to attract electrons to itself when it is chemically combined with another element
Electron Affinity: Amount of energy released when an atom gains an electron; how high a price the atom will pay for an electron
Electron Configuration: Shorthand notation that shows the number and arrangement of electrons
Empirical Definition: Defines an object or process in terms of observable properties
Empirical Formula: Simplest formula of a compound; lowest whole number ratio of elements)
Empirical Knowledge: Knowledge coming directly from observations
Endpoint: Point at which the indicator changes colour
First Ionization Energy: Energy required to remove the outermost electron of an atom; how tightly the electrons are bound
Half Life: Time taken for half of the original number of radioactive atoms to decay
Hydration: Involves an ion or molecule being surrounded by water molecules
Hydrogen Bonding: Strong intermolecular attraction between molecules with hydrogen atom that is covalently bonded to a highly electronegative atom; positive nucleus nearly bare
Indicator: Substance that changes colour in presence of an acid or base
Inner Transition Elements: Elements found at the bottom of the periodic table that would extend the table
Intramolecular Forces: Force within bonds to hold atoms or ions together; influence chemical properties
Intermolecular Forces: Force existing between ions and molecules; influence physical properties; forces of attraction and repulsion between molecules
Ionic Compound: Metal joining to a non-metal; metals lose electron(s) due to low ionization energy; non-metals gain electron(s) due to high electron affinities
Isotopes: Different forms of an element having the same atomic number but differ in the amount of neutrons
Lewis Dot Diagrams: Show only the valance shell of atoms
Mass Number: Sum of particles in nucleus (protons and neutrons)
Molar Mass: Mass, in grams per mole, of one mole of a substance; M = g/mol
Mole: Equal to 6.02 x 1023 entities
Molecular Compound: Non-metal