Basic Chemistry Powerpoint

• Matter


  Anything that occupies space and has mass (weight)
• States of matter


  • Solids
  • Liquids
  • Gasses
• Energy


  The ability to do work
• Forms of energy

  • Chemical
  • Electrical
  • Mechanical
  • Radiant
• Energy can easily be converted from 1 form to another but is not 100% efficient – some lost as heat
• Elements


  Fundamental units of matter – cannot be broken down into smaller units
• Elements that make up 96% of the body

  • Carbon (C)
  • Oxygen (O)
  • Hydrogen (H)
  • Nitrogen (N)
• Atoms


  Building blocks of elements
• Atomic structure


  • Protons (p+) in the nucleus
  • Neutrons (n0) in the nucleus
  • Electrons (e-) outside the nucleus

  
• Atomic number


  Equal to the number of protons that the atoms contain – also equals number of electrons
• Atomic mass number


  Sum of the protons and neutrons
• Isotopes


  Have the same number of protons and electrons so same atomic number, but vary in number of neutrons so different atomic masses
• Atomic weight


  Close to mass number of most abundant isotope, reflecting natural isotope variation
• Radioisotope


  Heavy isotope that is unstable and decomposes to more stable isotope
• Radioactivity


  Process of spontaneous atomic decay that releases particles – alpha, beta, and gamma rays
• Molecule


  Two or more atoms combined chemically
• Compound


  Two or more different atoms combined chemically
• Compounds have properties different from the properties of the atoms they are made of
• Chemical reactions


  Occur when atoms combine or dissociate from other atoms, united or dissociated by chemical bonds
• Electrons


  Occupy energy levels called electron levels or shells, with those closest to the nucleus most strongly attracted

  
• Each electron shell has a distinct upper limit on the number of electrons it can hold
• Shells closest to the nucleus usually fill first
• Bonding


  Involves interactions between electrons in the outer (valence) shell
• Full valence shells do not form bonds
• Inert elements


  Have complete valence shells and are stable, following the "rule of 8s"
• Reactive elements


  Have valence shells that are not full and are unstable, tending to gain, lose, or share electrons to form bonds

  
• Ionic bonds


  Form when electrons are completely transferred from one atom to another, creating oppositely charged ions that attract
• Covalent bonds


  Form when atoms share electrons, with single bonds sharing one electron and double bonds sharing two

  
• Polarity


  Some covalently bonded molecules are non-polar and electrically neutral, while others are polar with a positive and negative side
• Hydrogen bonds


  Weak chemical bonds where hydrogen is attracted to the negative portion of a polar molecule, providing attraction between molecules

  
• Synthesis reaction


  Atoms or molecules combine, with energy absorbed for bond formation - anabolic, constructive activities
• Decomposition reaction


  Molecule is broken down, with chemical energy released when bonds are broken - catabolic, decomposition activities
• Exchange reaction


  Involves both synthesis and decomposition, with a switch made between molecule parts to form different molecules
• Organic compounds


  Contain carbon, most are covalently bonded (e.g. glucose)
• Inorganic compounds


  Lack carbon, tend to be simpler (e.g. water)
• Water


  • High heat capacity
  • Polarity/solvent properties
  • Chemical reactivity
  • Cushioning
• Salts


  Easily dissociate into ions in the presence of polar water molecules, vital to many body functions including as electrolytes
• Acids


  Can release detectable hydrogen ions, have a sour taste and can "burn", act as proton donors
• Bases


  Have a bitter taste and are slippery, act as proton acceptors
• Neutralization reaction


  Acids and bases react to form water and a salt