Science 9 Chemistry Concept Map

Properties of Materials

• Materials can be classified by physical and chemical properties.
• Pure substances consist of one type of matter with unique properties (e.g., elements and compounds).
• Mixtures are combinations of pure substances that do not chemically combine; can be classified as mechanical mixtures or solutions.

Types of Mixtures

• Mechanical Mixture: Visible different substances (e.g., soil, frozen vegetables).
• Solution: Homogeneous mixture where one substance is dissolved in another (e.g., sugar in coffee).
• Suspension: Cloudy mixture with tiny particles that can be filtered (e.g., tomato juice).
• Colloid: Cloudy mixture where particles cannot be easily separated (e.g., milk, ketchup).

Chemical Change and Evidence

• Chemical change results in the formation of new substances; reactants combine to produce products.
• Evidence of chemical change includes color changes, formation of gas or solids, release or absorption of heat.

Safety in the Science Classroom

• Safety hazard symbols indicate potential dangers of materials used in science.
• WHMIS (Workplace Hazardous Materials Information System) provides standardized symbols for hazardous materials to improve safety.

The Periodic Table

• Consists of elements organized in rows (periods) and columns (groups/families) based on similar properties.
• Each element box contains its symbol, atomic number (number of protons), and can include the element's name and origins of its name.

Ionic and Molecular Compounds

• Ionic compounds are formed from metals and non-metals through transfer of electrons; represented with chemical formulas (e.g., NaCl).
• Molecular compounds form when non-metals combine, can exist as solids, liquids, or gases.

Chemical Reactions

• Involves the transformation of reactants into products with observable changes.
• Reactants: substances that undergo change; Products: new substances formed.
• The Law of Conservation of Mass states that mass is conserved in chemical reactions, where total mass of reactants equals total mass of products.

Rate of Chemical Reactions

• Four factors influencing reaction rates: presence of catalysts, concentration of reactants, temperature, and surface area.
• Catalysts speed up reactions without being consumed; common examples include enzymes in biological systems.

Exothermic and Endothermic Reactions

• Exothermic reactions release heat (e.g., combustion).
• Endothermic reactions absorb heat (e.g., cold packs).

Common Chemical Processes

• Combustion: reaction of a substance with oxygen to produce heat and light.
• Corrosion: slow reaction between a metal and oxygen, leading to rusting (e.g., iron to iron oxide).
• Cellular respiration: converts glucose and oxygen into energy, water, and carbon dioxide in cells.

Naming Ionic Compounds

• Roman numerals are used in the names of transitions metals to indicate the charge of the ion used (e.g., CuSO4 as Copper (II) Sulfate).
• The naming convention includes writing the metal first and changing the non-metal name to end in -ide.

Flashcard Creation for WHMIS Symbols

• Create flashcards for safety symbols to aid memorization, including hazard symbols and their corresponding products.