matter & separation techniques

• Chemistry is considered the central science because its concepts are at the core of other sciences and applied sciences
• Chemistry is the study of matter, its properties, the changes that matter undergoes, and the energy associated with these changes
• Matter is anything that has both mass and volume and takes up space
• Composition refers to the types and amounts of simpler substances that make up a sample of matter
• Properties are the characteristics that give each substance a unique identity
• Five key points in studying matter are composition, properties, structure, change, and energy
• Physical properties are properties of a substance shown by itself without interacting with another substance
• Intensive (intrinsic) properties do not depend on the amount of matter and include melting/boiling point, density, odor, and color
• Extensive (extrinsic) properties depend on the amount of matter and include mass and volume
• Chemical properties are properties that show as a substance interacts with or transforms into other substances
• Examples of chemical properties include acidity, flammability, reactivity, toxicity, and combustion
• Physical change is when the physical state changes but not the chemical composition
• Chemical change is when the chemical composition changes and is irreversible
• States of matter include solid, liquid, gas, and plasma
• Solid has a fixed shape and volume with high intermolecular forces (IMF)
• Liquid has varying shape, fixed volume, and an upper surface
• Gas has no fixed shape or volume and no surface
• Plasma is similar to gases but made up of free electrons and ions, examples include stars and neon lights
• Bose-Einstein Condensate forms below a critical temperature where all bosons fall into the same quantum state
• Fermionic Condensate is produced by cooling fermionic particles to low temperatures, forming a superfluid phase
• Phase changes occur due to thermodynamics, with endothermic reactions absorbing heat and exothermic reactions releasing heat
• Energy in chemistry is the ability to do work or transfer heat, conserved and can be converted from one form to another
• Pure substance:

  • Has a fixed chemical composition
  • Elements consist of atoms with the same number of protons
  • Molecule: 2 or more atoms chemically bound together
  • 118 elements in total, 94 occur naturally, 24 are synthetic
  • Elements classified as metals, nonmetals, and metalloids
• Compounds:

  • Composed of two or more elements in a fixed ratio
  • Classified as acids, bases, and salts based on pH levels
• Arrangement of elements:

  • Groups or families: vertical arrangement with same chemical properties
  • Periods or series: horizontal arrangement with same core elements and main energy levels
  • Elements named after famous people, place of discovery, heavenly bodies, or minerals
  • Atomic number is the number of protons, atomic mass is the average mass of atoms
• Mixtures:

  • Two or more substances mixed by physical means
  • Heterogeneous mixtures do not blend and can be separated
  • Homogeneous mixtures have uniform composition throughout
• Separation techniques:

  • Mechanical separation: using physical properties like color and shape
  • Magnetic separation: utilizing magnetism
  • Decantation: pouring off liquid to leave another liquid or solid behind
  • Filtration: using a filter paper to separate solid and liquid particles
  • Extraction: removing one substance from a mixture based on solubility
  • Distillation: using heating and cooling to separate components of a liquid mixture
  • Centrifugation: circular motion to help denser components sink faster
  • Paper chromatography: using molecular attraction to separate mixtures