Chemistry Fundamentals

Definition of Matter

• Matter: Substance that has mass and occupies space.
• Examples: Humans, airplanes, Atlantic Ocean.
• Cannot directly see it, but can feel its presence (like air).

Building Blocks of Matter

• Atoms: Smallest unit of matter retaining specific properties.
• Elements: Pure substances that cannot be broken down further.
  • Organize elements on the periodic table.
  • Example of elements: Carbon, Hydrogen, Oxygen.

Elements and Compounds

• Carbon:
  • Exists in forms like graphite.
  • Graphite is made of pure carbon.
• Water (H₂O):
  • Made from hydrogen and oxygen.
  • Molecules can have different properties from their constituent atoms.
• Compounds:
  • Formed when atoms from different elements chemically interact.
  • Unique names based on element combinations and ratios.
  • Example: Water (H₂O) vs. Hydrogen Peroxide (H₂O₂).

Mixtures

• Homogeneous Mixtures: Uniform composition.
  • Example: Salt water (sodium and chloride ions spread evenly).
• Heterogeneous Mixtures: Non-uniform composition.
  • Example: Muddy water (settles over time).
• Components in mixtures are not chemically bound.
• Methods of Separation: Filtration, magnetism, distillation, chromatography, crystallization.

States of Matter

• Three general states: Solid, Liquid, Gas.
• Examples:
  • Ice (solid), Water (liquid), Vapor (gas).
• Kinetic Molecular Theory:
  • Explains behavior of matter based on particle motion and energy.
  • Energy changes affect state changes (endothermic vs. exothermic).
• State Changes:
  • Melting: Solid to liquid.
  • Vaporization: Liquid to gas.
  • Condensation: Gas to liquid.
  • Freezing: Liquid to solid.
  • Sublimation: Solid directly to gas.
  • Deposition: Gas directly to solid.

Temperature and Kelvin Scale

• Kelvin (K): SI unit to measure temperature; absolute scale.
  • Absolute zero (0 K): No kinetic energy, no particle movement.
  • Conversion: 0°C = 273.15 K.
  • Water boils: 100°C = 373.15 K.
  • Conversion formula: °C to K = °C + 273.15.
• Difference from Celsius: Kelvin only has positive values.

Summary

• Chemistry is foundationally about understanding matter and its interactions.
• Essential to grasp the concepts of atoms, elements, compounds, and mixtures.
• Understand physical states and the energy associated with state changes.
• Familiarize with temperature measurement in Kelvin for scientific accuracy.