Chemistry Safety, Bonding, and Reactions – Vocabulary Review

A comprehensive set of vocabulary flashcards covering laboratory safety, chemical bonding, reaction types, and acid-base chemistry as outlined in the lecture notes.

HHPS (Household Hazardous Product Symbols)

Pictograms found on consumer products that indicate the type and level of hazard; in HHPS, more sides on the border mean greater danger.

WHMIS (Workplace Hazardous Materials Information System)

Canada’s system of standardized labels and pictograms used to communicate hazards of chemicals in workplaces and laboratories.

Wafting

Safe lab technique of gently fanning vapours toward the nose to smell a chemical instead of inhaling directly.

STOP, DROP, and ROLL

Emergency procedure used to extinguish fire on a person’s clothing or body.

Compressed Gas (WHMIS)

Cylinder symbol indicating chemicals stored under pressure that may explode if heated or damaged.

Flammable and Combustible Material

Flame symbol warning that a substance can easily ignite and burn rapidly.

Oxidizing Material

Circular flame symbol indicating a substance that releases oxygen and can intensify fires or cause combustible materials to burn.

Corrosive Material

Test-tube eating hand/metal symbol showing a substance that can burn skin or corrode metals.

Dangerously Reactive Material

Exploding test-tube symbol for substances that may undergo vigorous reactions such as explosions or polymerization.

Poisonous & Infectious (Immediate, Serious Toxic Effects)

Skull-and-crossbones symbol indicating materials that can cause death or toxicity after short exposure.

Poisonous & Infectious (Other Toxic Effects)

T-shaped exclamation symbol for materials causing long-term health effects such as cancer or organ damage.

Biohazardous Infectious Material

Three-circle biohazard symbol warning of organisms or toxins that cause disease in humans or animals.

HHPS Shape Rule

Under HHPS, a triangle means caution, a diamond means warning, and an octagon means danger—the more sides, the greater the hazard.

Element

Pure substance made of only one kind of atom.

Compound

Substance composed of two or more different elements chemically combined in fixed ratios.

Ionic Compound

Compound formed from a metal and a non-metal held together by ionic bonds created through electron transfer.

Covalent Compound

Compound made of two (or more) non-metals bonded by shared pairs of electrons.

Ionic Bond

Electrostatic attraction between oppositely charged ions created by transfer of electrons.

Covalent Bond

Chemical bond formed when two atoms share one or more pairs of electrons.

Valence Electrons

Electrons in the outermost shell of an atom that participate in bonding.

Ion

Atom or group of atoms with a net electric charge due to loss or gain of electrons.

Cation

Positively charged ion formed when an atom loses electrons (often metals).

Anion

Negatively charged ion formed when an atom gains electrons (often non-metals).

Combining Capacity (Oxidation State)

Typical charge an atom attains when it forms an ion, used when writing formulas.

Roman Numeral System

Method of indicating an element’s specific combining capacity in compound names, e.g., iron(III) chloride.

Criss-Cross Method

Technique for writing ionic formulas by crossing the combining capacities of the ions to become subscripts.

Polyatomic Ion

A tightly bound group of atoms that acts as a single charged species, e.g., SO₄²⁻.

Chemical Reaction

Process in which chemical bonds break and new bonds form, rearranging atoms to create new substances.

Law of Conservation of Mass

Principle stating that mass is neither created nor destroyed in a chemical reaction; total mass of reactants equals total mass of products.

Reactants

Starting substances present before a chemical reaction occurs.

Products

New substances formed as a result of a chemical reaction.

Coefficient (in equations)

Whole number placed in front of a formula to indicate the quantity of molecules or moles in a balanced equation.

Subscript (in formulas)

Small number written to the lower right of a chemical symbol indicating the number of atoms of that element in the formula unit.

Diatomic Molecule

Molecule consisting of two identical atoms (e.g., O₂, N₂, H₂).

Synthesis Reaction

Reaction in which two or more reactants combine to form a single product (A + B → AB).

Decomposition Reaction

Reaction where one compound breaks into two or more simpler substances (AB → A + B).

Single Replacement Reaction

Reaction in which one element replaces another in a compound (AB + Z → AZ + B).

Double Replacement Reaction

Reaction where ions in two compounds exchange partners to form two new compounds (AB + XY → AX + BY).

Combustion Reaction

Rapid reaction of a substance with oxygen producing oxides and releasing heat and light.

Neutralization Reaction

Reaction between an acid and a base producing a salt and water.

Exothermic Reaction

Chemical reaction that releases energy to surroundings, usually as heat or light.

Endothermic Reaction

Chemical reaction that absorbs energy from surroundings.

Acid

Substance that produces hydrogen ions (H⁺) in aqueous solution; pH less than 7.

Base

Substance that produces hydroxide ions (OH⁻) in aqueous solution; pH greater than 7.

pH Scale

Logarithmic scale from 0–14 measuring acidity or basicity; each unit represents a 10× change in [H⁺].

Binary Acid

Acid composed of hydrogen and one non-metal; named with prefix “hydro-” and suffix “-ic acid” (e.g., HCl = hydrochloric acid).

Oxyacid

Acid containing hydrogen, oxygen, and another element; naming based on polyatomic ion (-ate → ‑ic acid, ‑ite → ‑ous acid).

Salt (Chemistry)

Ionic compound formed from the cation of a base and the anion of an acid during neutralization.

Acid-Base Indicator

Substance that changes colour depending on the pH of a solution.

Litmus Paper

Common indicator that turns red in acidic solutions and blue in basic solutions.

Dissociation

Process by which an ionic compound separates into ions when dissolved in water.

Hydrogen Ion (H⁺)

Proton released by acids in aqueous solution, responsible for acidic properties.

Hydroxide Ion (OH⁻)

Ion produced by bases in water, responsible for basic properties.

Metal Oxide

Ionic compound of a metal and oxygen that reacts with water to form a base.

Non-Metal Oxide

Covalent oxide that reacts with water to form an acid.

Ammonium Ion (NH₄⁺)

Common polyatomic cation with a +1 charge, often found in fertilizers and salts.

Stable Octet

Electron configuration with eight valence electrons providing chemical stability for most main-group elements.

Precipitate

Solid that forms and separates from solution during a chemical reaction.

Aqueous (aq)

State symbol indicating a substance dissolved in water.

State Symbols

Notations (s, l, g, aq) used in chemical equations to denote physical states of reactants and products.