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 $(\text{H}<em>2\text{O}</em>2)$ — 2 H : 2 O.
    • Water $(\text{H}_2\text{O})$ — 2 H : 1 O.
    • Table salt $\text{NaCl}$ (sodium + chlorine).
    • Sugar $\text{C}<em>{12}\text{H}</em>{22}\text{O}_{11}$.
    • 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 $(\text{Fe}<em>2\text{O}</em>3)$ (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: $T<em>{!^{\circ}\text{F}} = 1.8\,T</em>{!^{\circ}\text{C}} + 32$
• Fahrenheit → Celsius: $T<em>{!^{\circ}\text{C}} = \frac{T</em>{!^{\circ}\text{F}} - 32}{1.8}$
• Celsius → Kelvin: $T<em>{\text{K}} = T</em>{!^{\circ}\text{C}} + 273$

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).