The Nature and Structure of Matter

  1. Matter - anything that has mass and occupies space.
  1. States of Matter: Solid, Liquid, Gas, Plasma
  2. Particle arrangement:
  1. Solids: closely spaced, little movement & energy, doesn't change shape.
  2. Liquids: farther spaced, more movement & energy, changes shape.
  3. Gas: farthest apart, greatest movement and energy, changes shape.
  1. Crystalline and Noncrystalline (amorphous) solids
  2. Examples of Physical Properties (observable / measurable characteristics) of Matter:
  1. Hardness - firmness of object.
  2. Malleability - ability to be worked into different shapes.
  3. Ductility - ability to be drawn into a wire.
  4. Conductivity - ability to carry heat / electricity.
  5. Boiling point - temp. at which liquid turns to gas.
  6. Freezing point - temp. at which liquid turns to solid.
  7. Melting point – temp. at which solid turns to liquid.
  8. pH –measure of the hydronium ion concentration of a solution.
  9. Viscosity – resistance to flowing.
  10. Sensory characteristics: color, taste, smell, luster (shine of substance), texture.
  1. Chemical Properties of Matter (changes / reactions with other substances):
  1. Rust
  2. Burn
  3. React with other substances.
  1. Physical / Chemical Changes:
  1. Physical Changes: affects appearance only.

1. Signs of physical change:

  1. Size or shape changes.
  2. State changes - particles are rearranged:
  1. Types of state changes:
  1. Liquid to a gas: evaporation
  2. Gas to a liquid: condensation
  3. Solid to a liquid: melting
  4. Liquid to a solid: freezing
  5. Gas to a solid: deposition.
  6. Solid to a gas: sublimation
  1. Remember, due to conservation laws: mass before change = mass after change.
  1. Chemical changes: - affects appearance AND composition (due to rusting, burning, or reacting)
  1. New substance is formed with different chemical properties.
  2. Signs of a chemical change:
  1. Heat, light, or energy is given off.
  2. Chemical color change.
  3. Gas is given off.
  1. Density – physical property of matter determined by an object’s mass (matter) in relation to its volume.
  1. More mass in same volume = more density.
  2. More volume in same mass = less density.

  3. Example:


CarCrushed car

* greater volume* less volume

* less density* greater density

  1. Formula:

D = M / vD = density (g/mL, kg/L, g/ cm3)

m = D x vm = mass (g, kg, cg)

v = m / Dv = volume (mL, L, cm3)

1. D = m / v2. m = d x v

D = 15 kg / 5 cm3 m = 6 g/mL x 3 mL

D = 3 kg/cm3 m = 18 g

  1. Molecular Structure of Elements:
  1. Atom – smallest particle of an element with the same properties of the element.
  2. Element – consists of identical atoms.
  3. Molecule – atoms that are chemically joined, and the smallest part of a compound that still has properties of that compound.
  4. Compound – consists of identical molecules.
  5. Molecular structure of compounds (chemical combination):
  1. example: FeS2 (Iron disulfide) compound – fool’s gold.
  2. The smallest piece of the above compound is one molecule of FeS2 (one atom of Fe and two atoms of S).
  3. Iron and Sulfur have properties different than Iron disulfide.
  4. Compounds can ONLY be separated by chemical means.
  1. Molecular Structure of Mixtures (physical combination):
  1. Mixture – consists of substances that are NOT chemically bonded. It can be any combination of elements or compounds. Ex: gold jewelry is mixture of Au, Cu, and Ag.
  2. Mixtures can be separated by physical means:
  1. by hand
  2. by heating to different melting points
  3. by density (centrifuge)
  4. by evaporation
  5. by use of magnet
  6. by distillation
  7. by chromatography
  8. by solubility of a substance
  1. Solution – A mixture in which the particles are evenly distributed throughout.
  1. types:
  1. gaseous solutions (air)
  2. liquid solutions (sugar water, tea)
  3. solid solutions (steel, 14K gold)
  1. Solute – substance being dissolved. (instant tea mix)
  2. Solvent – substance dissolving the solute. (water for instant tea mix)
  3. Saturated solution – solution that has dissolved all the solute it can hold at a given temperature.
  1. Behavior / Uses of Some States of Matter:
  1. Behavior of Gases:
  1. Pressure – amount of force exerted per unit of area. P = F / A
  1. Units of pressure = Pa (pascal) or kPa
  2. 1 Pa = 1 N / m2
  3. Earth’s atmosphere exerts pressure on everything
  1. Boyle’s Law – If volume of gas is decreased, pressure is increased when temperature is constant. (balloon example)
  2. Charles’s Law – The volume of a gas increases with increase in temp. if pressure is constant. (hot air balloon example)
  1. Uses of Fluids:
  1. Bouyancy – ability of a fluid (liquid or gas) to exert an upward force on an object immersed in it.
  2. Archimedes’ Principle – buoyant force on an object in a fluid is equal to the weight of the fluid displaced by the object. (boat in water example)
  3. Pascal’s Principle – pressure applied to a fluid is transmitted unchanged throughout the fluid (toothpaste tube, hydraulics example)
  4. Bernoulli’s Principle – as the velocity of a fluid increases, the pressure exerted by the fluid decreases. (airplane wings, shower curtain examples)