Some Basic Chemistry

1
Some Basic Chemistry
2
Review Terms

• Elements
• Atom
• Atomic Mass
• Atomic Number
• Isotope
• Electron Shells
• Compound

• Molecule
• Molecular Mass
• Chemical Reactions
• Solute
• Solvent

3
Bonds

• Ionic Bonds- Transfer of electrons

4
(No Transcript)
5
Bonds

• Covalent- Sharing of electrons

6
(No Transcript)
7

• Polar- Shared unequally
• Nonpolar- Shared equally

8
Nonpolar
Polar
9
(No Transcript)
10
Bonds

• Hydrogen Bond- Between hydrogen of one molecule
  and oxygen or nitrogen of another molecule

11
(No Transcript)
12

• Sketch a molecule of water. Consider
• The type of bond that holds atoms within a
  molecule of water together
• The type of bond that holds molecules of water
  together
• How many water molecules can bind together?

13
Water

• 75 of a cell is water
• Polar Covalent Bond (Oxygen is negative)
• Any 1 water molecule can form up to 4 hydrogen
  bonds

14
(No Transcript)
15
Water

• Water is both cohesive and adhesive

16
Water

• Cohesion- holding together of like substances

17
Water

• Surface Tension- Due to cohesion

18
Water

• Adhesion- holding together of different substances

19
Water

• Capillary Action Allows water to rise against
  gravity

20
Water

• Has high Specific Heat
• Takes a lot of heat to raise its temperature and
  cools more slowly
• High Thermal Conductivity- heat spreads quickly

21
Water

• A good Evaporative Coolant
• Water vapor carries away a lot of heat.
  (molecules with most energy go away, taking heat)

22
Water

• Allows organisms to stay cool

Sweating
Panting
23
(No Transcript)
24
Water

• Water is a solvent of ions and other polar
  molecules
• Nonpolar substances do not dissolve (fats and
  oils)

25
(No Transcript)
26
(No Transcript)
27
pH Scale

• Measures the amount of H and OH- ions in water.
• Acids release more H ions
• Bases release more OH- ions (or one that accepts
  more H)

28
(No Transcript)
29
Buffers

• Keep pH consistent
• Take up or release H ions or OH- ions