Chemistry

• Topics covered


  • Radioactive dating
  • Nuclear fission
  • Nuclear fusion
  • Ionic bonding
  • Covalent bonding
  • Chemical reactions
  • Electrochemistry
  • Moles
  • Solutions
  • Acids and bases
  • Gases
  • Serendipitous discoveries in chemistry
• Radioactive dating


  Technique for determining the age of an object containing radioactive material
• Nuclear fission


  1. Breaking elements apart

  2. Mass defect

  3. Chain reactions and critical mass
• Nuclear fusion


  Coming together of elements
• Ionic bonding


  Bonding formed by the transfer of electrons between atoms
• Covalent bonding


  Bonding formed by the sharing of electrons between atoms
• Chemical reactions

  1. Reactants and products

  2. Collision theory

  3. Types of reactions

  4. Balancing chemical equations

  5. Chemical equilibrium

  6. Chemical kinetics

  7. Catalysts
• Electrochemistry


  1. Redox reactions

  2. Electrochemical cells
• Mole


  Unit used to measure the amount of a substance
• Solutions


  Mixtures of solutes and solvents
• Acids and bases


  Substances that can donate or accept protons
• Chemistry is a whole branch of science about matter, which is anything that has mass and occupies space
• Chemistry is the study of the composition and properties of matter and the changes it undergoes
• Matter and energy are the two basic components of the universe
• Change of state (phase change)

  1. Solid to liquid (melting)

  2. Liquid to gas (boiling)

  3. Gas to liquid (condensation)

  4. Liquid to solid (freezing)
• Melting point (mp)


  Temperature at which a solid melts and becomes a liquid
• Boiling point (bp)


  Temperature at which a liquid boils and becomes a gas
• The melting point is the same as the freezing point
• Sublimation


  Process where a solid goes directly to a gas without becoming a liquid
• Chemists can easily separate the different parts of a mixture by physical means, such as filtration
• Chemical property


  A property that enables a substance to change into a brand-new substance, and describes how a substance reacts with other substances
• Physical property


  A property that describes the physical characteristics of a substance
• Types of physical properties

  • Extensive (depend on amount of matter)

  Intensive (don't depend on amount of matter)
• Density


  The ratio of the mass (m) to volume (v) of a substance (d = m/v)
• The density of water at 20°C is 1 g/mL
• Calculating density


  Measure mass of object

  2. Determine object's volume

  3. Divide mass by volume
• Archimedes' principle


  The volume of a solid is equal to the volume of water it displaces
• Kinetic energy


  Energy of motion
• Potential energy


  Stored energy, such as energy stored in chemical bonds
• Energy is neither created nor destroyed, but it can be converted from one form to another
• Temperature


  A measure of the average kinetic energy of the particles in a substance
• Water boils at 100°C (373 K) and freezes at 0°C (273 K)
• Heat


  The amount of energy that goes from one substance to another
• 1 calorie = 4.184 joules
• Charge


  Like charges, whether positive or negative, repel each other, and objects with unlike charges attract each other
• Atom


  Has no charge, it's neutral
• Certain atoms can gain or lose electrons and acquire a charge, and atoms that gain a charge, either positive or negative, are called ions
• Protons and neutrons are located in the nucleus, a dense central core in the middle of the atom, and the electrons are located outside the nucleus
• Nucleus


  • It is very, very small and very, very dense when compared to the rest of the atom
  • Typically, atoms have diameters that measure around 10–10 meters, while nuclei are around 10–15 meters in diameter
• For all practical purposes, the mass of the atom is the sum of the masses of the protons and neutrons