Nature of Matter

• A matter is said to be composed of particles which are basically atoms and molecules
• Solid

  The substances in which the particles are held close to each other with strong intermolecular forces
• Liquid

  Those substances in which the intermolecular forces are weak enough to allow the movement of particles
• Gas

  These types of matter have very weak forces between their molecules and hence the molecules are free to move
• Macroscopic View –  includes anything seen with the naked eye.
• Microscopic View – is the technical field of using microscopes to view samples & objects that cannot be seen with the unaided eye.
• A substance is a type of matter that has the same properties and the same composition throughout a sample.
• Physical Change

  a substance temperature or pressure changes, or if it is mechanically manipulated, some of its physical properties may change.
• substance’s melting point, the temperature at which the solid melts
• the temperature at which the liquid freezes, the freezing point
• boiling point, the temperature at which the liquid boils
• Temperature - It is the property of matter that determines whether there can be heat energy transfer from one object to another. It is represented by the symbol “T”, and is usually measured in Celsius units.
• density - the ratio of the mass of a sample to its volume
• Chemical properties describe the characteristic ability of a substance to react to form new substances; they include its flammability and susceptibility to corrosion.
• extensive property is a property that depends on the amount of matter in a sample
• intensive property is a property of matter that depends only on the type of matter in a sample and not on the amount
• Matter is anything that occupies space and has mass.
• A physical change involves the conversion of a substance from one state of matter to another, without changing its chemical composition.
• Matter - Occupies space and possesses mass; may exist as solid, liguid, or gas
• Pure substance

  Matter having an invariant chemical composition and distinct properties
• Mixture

  Matter consisting of two or more pure substances that retain their individual identities and can be separated by physical methods
• Element

  Fundamental substance; cannot be separated into simpler substances by chemical methods
• Compound

  Substance composed of two or more elements in fixed proportions; can be separated into simpler substances and elements only by chemical methods*
• Homogeneous

  Mixture having a uniform composition and properties throughout (also called a solution)
• Heterogeneous

  Mixture not uniform in composition and properties throughout
• Here are a number of common separation techniques:

  1. Chromatography
  2. Distillation
  3. Evaporation
  4. Filtration
• Chromatography is the separation of a mixture by passing it in solution or suspension, or as a vapor (as in gas chromatography)
• Distillation is an effective method to separate mixtures that are comprised of two or more pure liquids.
• Evaporation is a technique used to separate out homogeneous mixtures that contain one or more dissolved salts.
• Filtration is a separation method used to separate out pure substances in mixtures comprised of particles