Matter, States, Properties, and Temperature Lecture Notes

Classification of Matter

• Matter: anything that has mass and occupies space; includes everyday examples (water, wood, plastic bags).

Major Divisions

• Pure Substances

  • Fixed/definite composition.
  • Two subclasses:
  • Elements
    • Contain only one kind of atom.
    • Examples & symbols: copper (Cu), lead (Pb), aluminum (Al).
    • Microscopic view: identical atoms packed together (e.g., aluminum can made purely of \text{Al} atoms).
  • Compounds
    • Two or more elements chemically combined in a constant ratio.
    • Examples (with formulas):
    • Hydrogen peroxide (\text{H}2\text{O}2) — 2 H : 2 O.
    • Water (\text{H}_2\text{O}) — 2 H : 1 O.
    • Table salt \text{NaCl} (sodium + chlorine).
    • Sugar \text{C}{12}\text{H}{22}\text{O}_{11}.
    • Decomposition of \text{NaCl} → metallic sodium + chlorine gas (illustrates that compounds contain elements).

• Mixtures

  • Physical combination of two or more substances; each retains its identity.
  • Proportions can vary.
  • Separable by physical methods (filtration, distillation, chromatography, straining spaghetti from water, etc.).
  • Two subclasses:
  • Homogeneous Mixtures (Solutions)
    • Uniform composition; components not visible.
    • Examples:
    • Brass (Cu + Zn atoms evenly distributed).
    • Scuba breathing mixtures:
      • Nitrox (O$2$ + N$2$).
      • Heliox (O$_2$ + He).
      • Trimix (O$2$ + He + N$2$).
  • Heterogeneous Mixtures
    • Composition varies; different parts visible.
    • Examples: copper metal in water, orange juice with pulp, salad.

Visual/Flow Summary (page 2 diagram textualized)

• Matter → Pure Substances → Elements / Compounds.
• Matter → Mixtures → Homogeneous / Heterogeneous.

Classification Exercise (Sample #1)

• Wine → homogeneous mixture.
• Gold → element.
• \text{CO}_2 → compound.
• Orange juice w/ pulp → heterogeneous mixture.

Separation Techniques for Mixtures

• Filtration: separates solids from liquids (lab funnel example).
• Paper Chromatography: components travel at different rates on paper surface.
• Physical straining: spaghetti + water.

Physical States of Matter

Solids

• Definite shape & volume.
• Particles: fixed, very close, vibrate slowly in rigid lattice.
• Strong attractive forces.
• Examples: ice, salt, iron, amethyst (purple quartz \text{SiO}_2), vitamin tablets, candles.

Liquids

• Definite volume; no definite shape (take container’s shape).
• Particles: random, close, move moderately.
• Examples: water, oil, vinegar, eye drops, vegetable oil.

Gases

• Neither definite shape nor volume (fill container).
• Particles: random, far apart, move very fast, essentially no attraction.
• Examples: water vapor, helium, air in basketball.

Comparative Table Highlights (from Table 3.1)

• Interaction strength: solids (very strong) > liquids (strong) > gases (none).
• Movement speed: very slow → moderate → very fast.
• Volume behavior: solids & liquids fixed; gases fill container.

Identification Exercise & Solution

• A vitamin tablet → solid.
• Eye drops → liquid.
• Vegetable oil → liquid.
• Candle → solid.
• Air in basketball → gas.

Physical vs. Chemical Properties & Changes

Physical Properties

• Observed/measured without changing identity: shape, state, color, melting/boiling points, density, luster.
• Copper example: reddish-orange, shiny, solid at 25\,^{\circ}\text{C}, \text{mp}=1083\,^{\circ}\text{C}, \text{bp}=2567\,^{\circ}\text{C}, good conductor.

Physical Changes

• Identity preserved; may involve change of state, size, or shape.
• Examples:
  • Water cycles through ice ↔ liquid ↔ steam.
  • Salt dissolves in water; crystals re-form on evaporation.
  • Gold ingot hammered into gold leaf.

Chemical Properties

• Describe ability to form new substances (reactivity with air, acids, etc.).

Chemical Changes

• Original substance → one or more new substances with new compositions/properties.
• Examples:
  • Iron + water/oxygen → rust (\text{Fe}2\text{O}3) (orange powder).
  • Sugar caramelizes when heated.
  • Burning wood → heat, ash, \text{CO}_2, water vapor.

Summary Table (Table 3.3 & 3.4 condensed)

• Physical Change examples: boiling water, drawing copper into wire, dissolving sugar, cutting paper.
• Chemical Change examples: silver tarnishes, magnesium burns, iron rusts, sugar caramelizes.

Property Identification Exercise (Sample #2)

• Silvery white, lustrous → physical.
• Melting at 649\,^{\circ}\text{C}, boiling at 1105\,^{\circ}\text{C} → physical.
• Density 1.738\,\text{g/cm}^3 → physical.
• Burns in air w/ white light → chemical.
• Reacts w/ chlorine → chemical.
• Malleable/ductile → physical.
• Conducts electricity → physical.

Change Identification Exercise (Sample #3)

• Rusting iron → chemical (cannot easily reverse).
• Sugar dissolving → physical.
• Burning a log → chemical.
• Melting ice → physical.
• Grinding cinnamon → physical.

Temperature

Concept & Measurement

• Indicates hotness or coldness relative to a standard.
• Measured with thermometers; scientific unit primarily Celsius (^{\circ}\text{C}).

Temperature Scales & Reference Points

• Celsius: water freezes at 0^{\circ}\text{C}, boils at 100^{\circ}\text{C} (100-unit interval).
• Fahrenheit: water freezes at 32^{\circ}\text{F}, boils at 212^{\circ}\text{F} (180-unit interval).
• Kelvin: absolute scale; 0\,\text{K} = -273^{\circ}\text{C} (absolute zero). Same-size units as Celsius; no negative values.

Inter-Conversion Equations

• Celsius → Fahrenheit: T{!^{\circ}\text{F}} = 1.8\,T{!^{\circ}\text{C}} + 32
• Fahrenheit → Celsius: T{!^{\circ}\text{C}} = \frac{T{!^{\circ}\text{F}} - 32}{1.8}
• Celsius → Kelvin: T{\text{K}} = T{!^{\circ}\text{C}} + 273

Worked Examples

• Room temperature 21^{\circ}\text{C} → T_{!^{\circ}\text{F}} = 1.8(21)+32 = 70^{\circ}\text{F}.
• Body temperature 37^{\circ}\text{C} → T_{\text{K}} = 37 + 273 = 310\,\text{K}.
• Winter day -15^{\circ}\text{F} → T_{!^{\circ}\text{C}} = \frac{-15 - 32}{1.8} \approx -26^{\circ}\text{C} (answer D in exercise).
• Hypothermia: 34.8^{\circ}\text{C} → T_{!^{\circ}\text{F}} = 1.8(34.8)+32 = 94.6^{\circ}\text{F}.

Temperature Comparison Snapshot (selected from Table 3.5)

• Sun surface: 5503^{\circ}\text{C} / 9937^{\circ}\text{F} / 5776\,\text{K}.
• Hot oven: 232^{\circ}\text{C}.
• Water boils: 100^{\circ}\text{C} = 212^{\circ}\text{F} = 373\,\text{K}.
• Room temperature: 21^{\circ}\text{C} = 70^{\circ}\text{F} = 294\,\text{K}.
• Absolute zero: -273^{\circ}\text{C} = -459^{\circ}\text{F} = 0\,\text{K}.

Health Connection: Body‐Temperature Extremes

• Hyperthermia
  • Body >41^{\circ}\text{C}.
  • Risk: convulsions, permanent brain damage.
  • Heatstroke at >41.1^{\circ}\text{C} → treat with ice-water immersion.
• Hypothermia
  • Body as low as 28.5^{\circ}\text{C}.
  • Treatment: oxygen, IV glucose + saline, warm fluid 37^{\circ}\text{C} peritoneal infusion to raise core temperature.

Key Takeaways & Connections

• Composition → Classification → Properties → Changes → Measurement (temperature) form a logical progression for understanding matter.
• Pure substances have constant composition; mixtures do not, but can be physically separated.
• States of matter differ in particle arrangement, motion, and interaction forces.
• Physical vs chemical properties/changes help predict material behavior and appropriate separation or synthesis strategies.
• Temperature conversions and scales are essential for laboratory safety, reaction control, and health applications.
• Real-world relevance: scuba gas mixtures (homogeneous solutions), cooking caramelization (chemical change), weather forecasts (°F ↔ °C conversion), medical thermometry (hyper/hypothermia thresholds).