**Properties of Matter** - **Physical vs Chemical Properties** - *Physical Properties:* Can be observed without changing the substance (e.g., color, density, melting point, boiling point) - *Chemical Properties:* Describe a substance’s ability to undergo chemical changes (e.g., flammability, reactivity with acid) - **Examples of Each** - Physical: Ice melting, water boiling, density, solubility - Chemical: Rusting iron, burning wood, tarnishing silver - **Intensive vs Extensive Properties** - *Intensive:* Do not depend on the amount of matter (e.g., density, boiling point, color) - *Extensive:* Depend on the amount of matter (e.g., mass, volume, length) --- **Density** - **Definition, Units, and Formula** - Density (ρ) = Mass (m) / Volume (V) - Units: g/cm³ (solids), g/mL (liquids), kg/m³ (gases) - **Comparison of Densities** - Solids: Generally highest density - Liquids: Lower density than solids but higher than gases - Gases: Lowest density - **Solid: Regular vs Irregular Shape** - *Regular Shape:* Use geometric formulas to find volume - *Irregular Shape:* Use water displacement method - **Factors Affecting Density** - Temperature (increase decreases density for most substances) - Pressure (affects gases significantly) - Composition (different materials have different densities) --- **Elements, Compounds, and Mixtures** - **Matter: Definition and Examples** - Anything that has mass and takes up space (e.g., air, water, rocks) - **Pure vs Impure Matter** - *Pure:* Elements and compounds (e.g., oxygen, water) - *Impure:* Mixtures (e.g., saltwater, air) - **Atom vs Element** - *Atom:* Smallest unit of an element - *Element:* Substance made of one type of atom - **Compounds vs Mixtures** - *Compounds:* Chemically bonded elements (e.g., H2O, CO2) - *Mixtures:* Physically combined substances (e.g., salad, air) - **Types of Mixtures** - Homogeneous (solutions, uniform throughout) - Heterogeneous (distinct parts, not uniform) - **Examples of Mixtures** - Homogeneous: Saltwater, air - Heterogeneous: Salad, granite --- **Solubility** - **Solutions** - *Parts:* Solute (dissolved substance) + Solvent (dissolving substance) - *Examples:* Saltwater (solute: salt, solvent: water) - **Effect of Temperature and Pressure** - Higher temperature increases solubility of solids in liquids - Higher pressure increases solubility of gases in liquids - **Gases vs Liquids** - Gases dissolve better in cold liquids under high pressure - Liquids dissolve better at higher temperatures - **Gaseous, Liquid, and Solid Solutions** - Gaseous: Air (oxygen in nitrogen) - Liquid: Saltwater (NaCl in H2O) - Solid: Alloys (brass, steel) - **Concentrations** - Unsaturated: Can dissolve more solute - Saturated: Maximum solute dissolved - Supersaturated: Holds more than normally possible - **Solubility Curve** - Shows solubility vs temperature - Higher points indicate higher solubility --- **The Mole** - **Avogadro’s Number** - 6.022 x 10^23 particles per mole - **Molar Mass** - Mass of one mole of a substance (g/mol) - **Particle, Mass, and Mole Calculations** - Particle calculations: Using Avogadro’s number - Mass calculations: Converting between grams and moles - Mole calculations: Determining amount of substance - **Moles at STP (Standard Temperature and Pressure)** - 1 mole of gas = 22.4 L at STP - **Atomic Mass Units (AMU)** - Unit for atomic/molecular mass --- **Labs** - **Density Lab** - Measure mass and volume, calculate density - Compare densities of different materials - **Elements, Compounds, and Mixtures Lab** - Classify substances based on their properties - **Mystery Powder Lab** - Identify unknown substances using solubility and reactions - **Cornstarch Lab** - Explore properties of non-Newtonian fluids This guide covers essential concepts in matter, density, solubility, and the mole, along with relevant lab activities

Silk Road

A vast network of trade routes established during the Han Dynasty of China around 130 BCE that connected the East to the West.

Goods traded along the Silk Road

Silk was the most valuable commodity, but spices, tea, porcelain, and precious metals were also traded.

Cultural Exchange on the Silk Road

The Silk Road facilitated the exchange of culture, religion, and technologies, such as the spread of Buddhism from India to China.

Key cities on the Silk Road

Samarkand and Bukhara in Central Asia, and Xi'an in China were major trading cities.

Impact of Geography on the Silk Road

The Silk Road traversed deserts, mountains, and rivers, influencing trade patterns and routes.

Decline of the Silk Road

The importance of the Silk Road waned with the rise of maritime trade routes in the late Middle Ages.

Innovations spread via the Silk Road

Papermaking and the compass traveled from the East to the West along these trade routes.

Han Dynasty

The Chinese dynasty during which the Silk Road was established, around 130 BCE.